WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003

Class	Cusip	Orig Prin Bal	Begin Prin Bal	Int Rate Accrued	Int Rate Paid	Int Dist	Prin Dist	Int Shortfall	Prin Loss	Deferred Interest	Int Reimbursed	Unscheduled Int	Prin Reimbursed	Total Dist	Ending Class Bal
IA1	929227QK5	$193,845,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA2	929227QL3	$100,000,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA3	929227QM1	$50,000,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA4	929227QN9	$15,000,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA5	929227QP4	$35,000,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA6	929227QQ2	$24,689,000.00	$22,240,536.12	6.5000000000%	6.5000000000%	$120,469.57	$4,762,293.88	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$4,882,763.45	$17,478,242.24
IA7	929227QR0	$40,000,000.00	$26,034,003.23	6.5000000000%	6.5000000000%	$141,017.52	$26,034,003.23	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$26,175,020.75	$0.00
IA8	929227QS8	$31,166,000.00	$33,614,463.88	6.5000000000%	6.5000000000%	$182,078.35	($182,078.35)	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$33,796,542.23
IA9	929227QT6	$56,000,000.00	$56,000,000.00	6.5000000000%	6.5000000000%	$303,333.33	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$303,333.33	$56,000,000.00
IA10	929227QU3	$50,000,000.00	$17,642,727.72	5.7500000000%	5.7500000000%	$84,538.07	$6,627,091.09	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$6,711,629.16	$11,015,636.63
IA11	929227QV1	$12,308,000.00	$12,308,000.00	6.5000000000%	6.5000000000%	$66,668.33	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$66,668.33	$12,308,000.00
IA12	929227QW9	$50,000,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA13	929227QX7	$2,922,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA14	929227QY5	$2,700,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA15	929227QZ2	$300,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA16	929227RA6	$5,769,230.00	$2,035,699.35	6.5000000000%	6.5000000000%	$11,026.70	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$11,026.70	$1,271,035.00
IA17	929227SA5	$500,000.00	$500,000.00	6.5000000000%	6.5000000000%	$2,708.33	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$2,708.33	$500,000.00
IIA1	929227RB4	$52,000,000.00	$14,232,748.20	5.7000000000%	5.7000000000%	$67,605.55	$4,345,124.45	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$4,412,730.00	$9,887,623.75
IIA2	929227RC2	$119,000,000.00	$28,739,203.08	6.0000000000%	6.0000000000%	$143,696.02	$8,773,808.97	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$8,917,504.99	$19,965,394.11
IIA21	XXXXXXXXX	$105,000,000.00	$28,739,203.08	6.0000000000%	6.0000000000%	$143,696.02	$8,773,808.97	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$8,917,504.99	$19,965,394.11
IIA22	XXXXXXXXX	$14,000,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA3	929227RD0	$25,000,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA4	929227RE8	$34,993,000.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA5	929227RF5	$13,527,000.00	$13,527,000.00	6.0000000000%	6.0000000000%	$67,635.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$67,635.00	$13,527,000.00
IIA6	929227SB3	$2,600,000.00	$711,637.41	6.0000000000%	6.0000000000%	$3,558.19	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$3,558.19	$494,381.19
IP	929227RG3	$2,304,936.00	$1,507,570.18	0.0000000000%	0.0000000000%	$0.00	$199,174.38	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$199,174.38	$1,308,395.80
IIP	929227RH1	$424,117.00	$198,095.09	0.0000000000%	0.0000000000%	$0.00	$44,689.36	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$44,689.36	$153,405.73
IB1	929227RJ7	$10,310,000.00	$10,183,304.46	6.5000000000%	6.5000000000%	$55,159.57	$9,746.90	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$64,906.46	$10,173,557.56
IB2	929227RK4	$3,780,000.00	$3,733,549.07	6.5000000000%	6.5000000000%	$20,223.39	$3,573.55	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$23,796.94	$3,729,975.52
IB3	929227RL2	$2,749,000.00	$2,715,218.62	6.5000000000%	6.5000000000%	$14,707.43	$2,598.86	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$17,306.29	$2,712,619.76
IB4	929227RR9	$1,374,000.00	$1,357,115.47	6.5000000000%	6.5000000000%	$7,351.04	$1,298.96	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$8,650.00	$1,355,816.51

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003

Class	Cusip	Orig Prin Bal	Begin Prin Bal	Int Rate Accrued	Int Rate Paid	Int Dist	Prin Dist	Int Shortfall	Prin Loss	Deferred Interest	Int Reimbursed	Unscheduled Int	Prin Reimbursed	Total Dist	Ending Class Bal
IB5	929227RS7	$1,031,000.00	$1,018,330.45	6.5000000000%	6.5000000000%	$5,515.96	$974.69	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$6,490.65	$1,017,355.76
IB6	929227RT5	$1,376,873.00	$1,359,953.44	6.5000000000%	6.5000000000%	$7,366.41	$1,301.67	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$8,668.09	$1,358,651.77
IIB1	929227RM0	$1,861,000.00	$1,769,095.40	6.0000000000%	6.0000000000%	$8,845.48	$6,916.26	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$15,761.74	$1,762,179.14
IIB2	929227RN8	$372,000.00	$353,628.96	6.0000000000%	6.0000000000%	$1,768.14	$1,382.51	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$3,150.65	$352,246.45
IIB3	929227RP3	$372,000.00	$353,628.96	6.0000000000%	6.0000000000%	$1,768.14	$1,382.51	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$3,150.65	$352,246.45
IIB4	929227RX6	$248,000.00	$235,752.65	6.0000000000%	6.0000000000%	$1,178.76	$921.67	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$2,100.44	$234,830.98
IIB5	929227RY4	$124,000.00	$117,876.33	6.0000000000%	6.0000000000%	$589.38	$460.84	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$1,050.22	$117,415.49
IIB6	929227RZ1	$249,483.00	$237,162.57	6.0000000000%	6.0000000000%	$1,185.81	$927.18	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$2,113.00	$236,235.39
R	929227RQ1	$50.00	$0.00	0.0000000000%	0.0000000000%	$0.03	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.03	$0.00
R_SYN	XXXXXXXXX	$0.00	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
Total		$935,526,459.00	$249,978,963.88			$1,319,994.52	$50,635,592.61	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$51,955,587.13	$199,343,371.27

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003

Class	Orig Face	Beg Bal	Prin Loss	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
IA1	$193,845,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA2	$100,000,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA3	$50,000,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA4	$15,000,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA5	$35,000,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA6	$24,689,000.00	$22,240,536.12	$0.00	$0.00	$4,762,293.88	0.7079364186	$17,478,242.24
IA7	$40,000,000.00	$26,034,003.23	$0.00	$0.00	$26,034,003.23	0.0000000000	$0.00
IA8	$31,166,000.00	$33,614,463.88	$0.00	$0.00	($182,078.35)	1.0844042299	$33,796,542.23
IA9	$56,000,000.00	$56,000,000.00	$0.00	$0.00	$0.00	1.0000000000	$56,000,000.00
IA10	$50,000,000.00	$17,642,727.72	$0.00	$0.00	$6,627,091.09	0.2203127326	$11,015,636.63
IA11	$12,308,000.00	$12,308,000.00	$0.00	$0.00	$0.00	1.0000000000	$12,308,000.00
IA12	$50,000,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA13	$2,922,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA14	$2,700,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA15	$300,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IA16	$5,769,230.00	$2,035,699.35	$0.00	$0.00	$0.00	0.2203127627	$1,271,035.00
IA17	$500,000.00	$500,000.00	$0.00	$0.00	$0.00	1.0000000000	$500,000.00
IIA1	$52,000,000.00	$14,232,748.20	$0.00	$0.00	$4,345,124.45	0.1901466106	$9,887,623.75
IIA2	$119,000,000.00	$28,739,203.08	$0.00	$0.00	$8,773,808.97	0.1677764211	$19,965,394.11
IIA21	$105,000,000.00	$28,739,203.08	$0.00	$0.00	$8,773,808.97	0.1901466106	$19,965,394.11
IIA22	$14,000,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIA3	$25,000,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIA4	$34,993,000.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
IIA5	$13,527,000.00	$13,527,000.00	$0.00	$0.00	$0.00	1.0000000000	$13,527,000.00
IIA6	$2,600,000.00	$711,637.41	$0.00	$0.00	$0.00	0.1901466115	$494,381.19
IP	$2,304,936.00	$1,507,570.18	$0.00	$0.00	$199,174.38	0.5676495139	$1,308,395.80
IIP	$424,117.00	$198,095.09	$0.00	$0.00	$44,689.36	0.3617061566	$153,405.73
IB1	$10,310,000.00	$10,183,304.46	$0.00	$0.00	$9,746.90	0.9867660097	$10,173,557.56
IB2	$3,780,000.00	$3,733,549.07	$0.00	$0.00	$3,573.55	0.9867660106	$3,729,975.52
IB3	$2,749,000.00	$2,715,218.62	$0.00	$0.00	$2,598.86	0.9867660095	$2,712,619.76
IB4	$1,374,000.00	$1,357,115.47	$0.00	$0.00	$1,298.96	0.9867660189	$1,355,816.51

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003

Class	Orig Face	Beg Bal	Prin Loss	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
IB5	$1,031,000.00	$1,018,330.45	$0.00	$0.00	$974.69	0.9867660136	$1,017,355.76
IB6	$1,376,873.00	$1,359,953.44	$0.00	$0.00	$1,301.67	0.9867662232	$1,358,651.77
IIB1	$1,861,000.00	$1,769,095.40	$0.00	$0.00	$6,916.26	0.9468990543	$1,762,179.14
IIB2	$372,000.00	$353,628.96	$0.00	$0.00	$1,382.51	0.9468990591	$352,246.45
IIB3	$372,000.00	$353,628.96	$0.00	$0.00	$1,382.51	0.9468990591	$352,246.45
IIB4	$248,000.00	$235,752.65	$0.00	$0.00	$921.67	0.9468991129	$234,830.98
IIB5	$124,000.00	$117,876.33	$0.00	$0.00	$460.84	0.9468991129	$117,415.49
IIB6	$249,483.00	$237,162.57	$0.00	$0.00	$927.18	0.9468997487	$236,235.39
R	$50.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
R_SYN	$0.00	$0.00	$0.00	$0.00	$0.00	0.0000000000	$0.00
Total	$935,526,459.00	$249,978,963.88	$0.00	$0.00	$50,635,592.61	0.2130814894	$199,343,371.27

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003
PER $1000 DENOMINATION
Class	Orig Face	Beg Bal	Prin Loss	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
IA1	$193,845,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA2	$100,000,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA3	$50,000,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA4	$15,000,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA5	$35,000,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA6	$24,689,000.00	900.82774191	0.00000000	0.00000000	192.89132326	0.7079364186	707.93641865
IA7	$40,000,000.00	650.85008075	0.00000000	0.00000000	650.85008075	0.0000000000	0.00000000
IA8	$31,166,000.00	1,078.56201887	0.00000000	0.00000000	-5.84221106	1.0844042299	1,084.40422993
IA9	$56,000,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IA10	$50,000,000.00	352.85455440	0.00000000	0.00000000	132.54182180	0.2203127326	220.31273260
IA11	$12,308,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IA12	$50,000,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA13	$2,922,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA14	$2,700,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA15	$300,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IA16	$5,769,230.00	352.85460105	0.00000000	0.00000000	0.00000000	0.2203127627	220.31276271
IA17	$500,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IIA1	$52,000,000.00	273.70669615	0.00000000	0.00000000	83.56008558	0.1901466106	190.14661058
IIA2	$119,000,000.00	241.50590824	0.00000000	0.00000000	73.72948714	0.1677764211	167.77642109
IIA21	$105,000,000.00	273.70669600	0.00000000	0.00000000	83.56008543	0.1901466106	190.14661057
IIA22	$14,000,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIA3	$25,000,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIA4	$34,993,000.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
IIA5	$13,527,000.00	1,000.00000000	0.00000000	0.00000000	0.00000000	1.0000000000	1,000.00000000
IIA6	$2,600,000.00	273.70669615	0.00000000	0.00000000	0.00000000	0.1901466115	190.14661154
IP	$2,304,936.00	654.06162254	0.00000000	0.00000000	86.41210862	0.5676495139	567.64951391
IIP	$424,117.00	467.07651426	0.00000000	0.00000000	105.37035771	0.3617061566	361.70615656
IB1	$10,310,000.00	987.71139282	0.00000000	0.00000000	0.94538312	0.9867660097	986.76600970
IB2	$3,780,000.00	987.71139418	0.00000000	0.00000000	0.94538360	0.9867660106	986.76601058
IB3	$2,749,000.00	987.71139323	0.00000000	0.00000000	0.94538378	0.9867660095	986.76600946
IB4	$1,374,000.00	987.71140466	0.00000000	0.00000000	0.94538574	0.9867660189	986.76601892

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003
PER $1000 DENOMINATION
Class	Orig Face	Beg Bal	Prin Loss	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
IB5	$1,031,000.00	987.71139670	0.00000000	0.00000000	0.94538312	0.9867660136	986.76601358
IB6	$1,376,873.00	987.71160448	0.00000000	0.00000000	0.94538131	0.9867662232	986.76622317
IIB1	$1,861,000.00	950.61547555	0.00000000	0.00000000	3.71642128	0.9468990543	946.89905427
IIB2	$372,000.00	950.61548387	0.00000000	0.00000000	3.71642473	0.9468990591	946.89905914
IIB3	$372,000.00	950.61548387	0.00000000	0.00000000	3.71642473	0.9468990591	946.89905914
IIB4	$248,000.00	950.61552419	0.00000000	0.00000000	3.71641129	0.9468991129	946.89911290
IIB5	$124,000.00	950.61556452	0.00000000	0.00000000	3.71645161	0.9468991129	946.89911290
IIB6	$249,483.00	950.61615421	0.00000000	0.00000000	3.71640553	0.9468997487	946.89974868
R	$50.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000
R_SYN	$0.00	0.00000000	0.00000000	0.00000000	0.00000000	0.0000000000	0.00000000

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003

Class	Orig Face	Int Rate Accrued	Int Rate Paid	Beg Cert Prin/Not Bal	Curent Int Accrued	Int Shortfall	Unscheduled Int	Int Reimbursed	Total Int Dist
IA1	$193,845,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA2	$100,000,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA3	$50,000,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA4	$15,000,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA5	$35,000,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA6	$24,689,000.00	6.5000000000%	6.5000000000%	$22,240,536.12	$120,469.57	$0.00	$0.00	$0.00	$120,469.57
IA7	$40,000,000.00	6.5000000000%	6.5000000000%	$26,034,003.23	$141,017.52	$0.00	$0.00	$0.00	$141,017.52
IA8	$31,166,000.00	6.5000000000%	6.5000000000%	$33,614,463.88	$182,078.35	$0.00	$0.00	$0.00	$182,078.35
IA9	$56,000,000.00	6.5000000000%	6.5000000000%	$56,000,000.00	$303,333.33	$0.00	$0.00	$0.00	$303,333.33
IA10	$50,000,000.00	5.7500000000%	5.7500000000%	$17,642,727.72	$84,538.07	$0.00	$0.00	$0.00	$84,538.07
IA11	$12,308,000.00	6.5000000000%	6.5000000000%	$12,308,000.00	$66,668.33	$0.00	$0.00	$0.00	$66,668.33
IA12	$50,000,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA13	$2,922,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA14	$2,700,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA15	$300,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IA16	$5,769,230.00	6.5000000000%	6.5000000000%	$2,035,699.35	$11,026.70	$0.00	$0.00	$0.00	$11,026.70
IA17	$500,000.00	6.5000000000%	6.5000000000%	$500,000.00	$2,708.33	$0.00	$0.00	$0.00	$2,708.33
IIA1	$52,000,000.00	5.7000000000%	5.7000000000%	$14,232,748.20	$67,605.55	$0.00	$0.00	$0.00	$67,605.55
IIA2	$119,000,000.00	6.0000000000%	6.0000000000%	$28,739,203.08	$143,696.02	$0.00	$0.00	$0.00	$143,696.02
IIA21	$105,000,000.00	6.0000000000%	6.0000000000%	$28,739,203.08	$143,696.02	$0.00	$0.00	$0.00	$143,696.02
IIA22	$14,000,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA3	$25,000,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA4	$34,993,000.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
IIA5	$13,527,000.00	6.0000000000%	6.0000000000%	$13,527,000.00	$67,635.00	$0.00	$0.00	$0.00	$67,635.00
IIA6	$2,600,000.00	6.0000000000%	6.0000000000%	$711,637.41	$3,558.19	$0.00	$0.00	$0.00	$3,558.19
IP	$2,304,936.00	0.0000000000%	0.0000000000%	$1,507,570.18	$0.00	$0.00	$0.00	$0.00	$0.00
IIP	$424,117.00	0.0000000000%	0.0000000000%	$198,095.09	$0.00	$0.00	$0.00	$0.00	$0.00
IB1	$10,310,000.00	6.5000000000%	6.5000000000%	$10,183,304.46	$55,159.57	$0.00	$0.00	$0.00	$55,159.57
IB2	$3,780,000.00	6.5000000000%	6.5000000000%	$3,733,549.07	$20,223.39	$0.00	$0.00	$0.00	$20,223.39
IB3	$2,749,000.00	6.5000000000%	6.5000000000%	$2,715,218.62	$14,707.43	$0.00	$0.00	$0.00	$14,707.43
IB4	$1,374,000.00	6.5000000000%	6.5000000000%	$1,357,115.47	$7,351.04	$0.00	$0.00	$0.00	$7,351.04

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003

Class	Orig Face	Int Rate Accrued	Int Rate Paid	Beg Cert Prin/Not Bal	Curent Int Accrued	Int Shortfall	Unscheduled Int	Int Reimbursed	Total Int Dist
IB5	$1,031,000.00	6.5000000000%	6.5000000000%	$1,018,330.45	$5,515.96	$0.00	$0.00	$0.00	$5,515.96
IB6	$1,376,873.00	6.5000000000%	6.5000000000%	$1,359,953.44	$7,366.41	$0.00	$0.00	$0.00	$7,366.41
IIB1	$1,861,000.00	6.0000000000%	6.0000000000%	$1,769,095.40	$8,845.48	$0.00	$0.00	$0.00	$8,845.48
IIB2	$372,000.00	6.0000000000%	6.0000000000%	$353,628.96	$1,768.14	$0.00	$0.00	$0.00	$1,768.14
IIB3	$372,000.00	6.0000000000%	6.0000000000%	$353,628.96	$1,768.14	$0.00	$0.00	$0.00	$1,768.14
IIB4	$248,000.00	6.0000000000%	6.0000000000%	$235,752.65	$1,178.76	$0.00	$0.00	$0.00	$1,178.76
IIB5	$124,000.00	6.0000000000%	6.0000000000%	$117,876.33	$589.38	$0.00	$0.00	$0.00	$589.38
IIB6	$249,483.00	6.0000000000%	6.0000000000%	$237,162.57	$1,185.81	$0.00	$0.00	$0.00	$1,185.81
R	$50.00	0.0000000000%	0.0000000000%	$0.00	$0.03	$0.00	$0.00	$0.00	$0.03
R_SYN	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
Total	$935,526,459.00			$249,978,963.88	$1,319,994.52	$0.00	$0.00	$0.00	$1,319,994.52

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003
PER $1000 DENOMINATION
Class	Orig Face	Int Rate Accrued	Int Rate Paid	Beg Cert Prin/Not Bal	Curent Int Accrued	Int Shortfall	Unscheduled Int	Int Reimbursed	Total Int Dist
IA1	$193,845,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA2	$100,000,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA3	$50,000,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA4	$15,000,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA5	$35,000,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA6	$24,689,000.00	6.5000000000%	6.5000000000%	900.82774191	4.87948358	0.00000000	0.00000000	0.00000000	4.87948358
IA7	$40,000,000.00	6.5000000000%	6.5000000000%	650.85008075	3.52543800	0.00000000	0.00000000	0.00000000	3.52543800
IA8	$31,166,000.00	6.5000000000%	6.5000000000%	1,078.56201887	5.84221106	0.00000000	0.00000000	0.00000000	5.84221106
IA9	$56,000,000.00	6.5000000000%	6.5000000000%	1,000.00000000	5.41666661	0.00000000	0.00000000	0.00000000	5.41666661
IA10	$50,000,000.00	5.7500000000%	5.7500000000%	352.85455440	1.69076140	0.00000000	0.00000000	0.00000000	1.69076140
IA11	$12,308,000.00	6.5000000000%	6.5000000000%	1,000.00000000	5.41666640	0.00000000	0.00000000	0.00000000	5.41666640
IA12	$50,000,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA13	$2,922,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA14	$2,700,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA15	$300,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IA16	$5,769,230.00	6.5000000000%	6.5000000000%	352.85460105	1.91129492	0.00000000	0.00000000	0.00000000	1.91129492
IA17	$500,000.00	6.5000000000%	6.5000000000%	1,000.00000000	5.41666000	0.00000000	0.00000000	0.00000000	5.41666000
IIA1	$52,000,000.00	5.7000000000%	5.7000000000%	273.70669615	1.30010673	0.00000000	0.00000000	0.00000000	1.30010673
IIA2	$119,000,000.00	6.0000000000%	6.0000000000%	241.50590824	1.20752958	0.00000000	0.00000000	0.00000000	1.20752958
IIA21	$105,000,000.00	6.0000000000%	6.0000000000%	273.70669600	1.36853352	0.00000000	0.00000000	0.00000000	1.36853352
IIA22	$14,000,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIA3	$25,000,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIA4	$34,993,000.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIA5	$13,527,000.00	6.0000000000%	6.0000000000%	1,000.00000000	5.00000000	0.00000000	0.00000000	0.00000000	5.00000000
IIA6	$2,600,000.00	6.0000000000%	6.0000000000%	273.70669615	1.36853462	0.00000000	0.00000000	0.00000000	1.36853462
IP	$2,304,936.00	0.0000000000%	0.0000000000%	654.06162254	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IIP	$424,117.00	0.0000000000%	0.0000000000%	467.07651426	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000
IB1	$10,310,000.00	6.5000000000%	6.5000000000%	987.71139282	5.35010378	0.00000000	0.00000000	0.00000000	5.35010378
IB2	$3,780,000.00	6.5000000000%	6.5000000000%	987.71139418	5.35010317	0.00000000	0.00000000	0.00000000	5.35010317
IB3	$2,749,000.00	6.5000000000%	6.5000000000%	987.71139323	5.35010186	0.00000000	0.00000000	0.00000000	5.35010186
IB4	$1,374,000.00	6.5000000000%	6.5000000000%	987.71140466	5.35010189	0.00000000	0.00000000	0.00000000	5.35010189

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003
PER $1000 DENOMINATION
Class	Orig Face	Int Rate Accrued	Int Rate Paid	Beg Cert Prin/Not Bal	Curent Int Accrued	Int Shortfall	Unscheduled Int	Int Reimbursed	Total Int Dist
IB5	$1,031,000.00	6.5000000000%	6.5000000000%	987.71139670	5.35010669	0.00000000	0.00000000	0.00000000	5.35010669
IB6	$1,376,873.00	6.5000000000%	6.5000000000%	987.71160448	5.35010128	0.00000000	0.00000000	0.00000000	5.35010128
IIB1	$1,861,000.00	6.0000000000%	6.0000000000%	950.61547555	4.75307899	0.00000000	0.00000000	0.00000000	4.75307899
IIB2	$372,000.00	6.0000000000%	6.0000000000%	950.61548387	4.75306452	0.00000000	0.00000000	0.00000000	4.75306452
IIB3	$372,000.00	6.0000000000%	6.0000000000%	950.61548387	4.75306452	0.00000000	0.00000000	0.00000000	4.75306452
IIB4	$248,000.00	6.0000000000%	6.0000000000%	950.61552419	4.75306452	0.00000000	0.00000000	0.00000000	4.75306452
IIB5	$124,000.00	6.0000000000%	6.0000000000%	950.61556452	4.75306452	0.00000000	0.00000000	0.00000000	4.75306452
IIB6	$249,483.00	6.0000000000%	6.0000000000%	950.61615421	4.75306935	0.00000000	0.00000000	0.00000000	4.75306935
R	$50.00	0.0000000000%	0.0000000000%	0.00000000	0.60000000	0.00000000	0.00000000	0.00000000	0.60000000
R_SYN	$0.00	0.0000000000%	0.0000000000%	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000	0.00000000

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
08/2003 DISTRIBUTION REPORT
SERIES: WAMU 02S3 WEIGHTED AVERAGE PC RATE: 6.44848%
POOL NUMBER: 1864
ISSUE DATE: 05/28/2002
CERTIFICATE BALANCE AT ISSUE: $687,355,859.44
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	438		$190,214,773.28
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$182,270.38
Unscheduled Principal Collection/Reversals		$18,809.36
Liquidations-in-full	83	$37,258,899.12
Net principal Distributed		$37,459,978.86	-$37,459,978.86

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	355		$152,754,794.42

SCHEDULED INTEREST AT MORTGAGE RATE:		$1,110,555.02

UNSCHEDULED INTEREST AT MORTGAGE RATE:
Unscheduled Interest Collection/Reversals		$0.00
Interest Uncollected on Liquidation		$0.00
Interest Uncollected on Non-Earning Assets		$0.00
Net Unscheduled Interest Distributed		$0.00

OTHER:
Loan Conversion Fees		$0.00
Expense Reimbursements		$0.00
Gain on Liquidations		$0.00
Hazard Insurance Premium Refunds		$0.00
Net Other Distributions		$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
08/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$88,391.00

UNSCHEDULED SERVICING FEES:
Unscheduled Service Fee Collections/Reversals		$0.00
Servicing Fees Uncollected on Liquidation		$0.00
Servicing Fees Uncollected/Non-Earning Assets		$0.00
Net Unscheduled Service Fees Distributed		$0.00

MISCELLANEOUS EXPENSES:		$0.00

NET FUNDS DISTRIBUTED:		$38,482,142.88

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
08/2003 DISTRIBUTION REPORT
SERIES: WAMU 02S3 WEIGHTED AVERAGE PC RATE: 5.98011%
POOL NUMBER: 1865
ISSUE DATE: 05/28/2002
CERTIFICATE BALANCE AT ISSUE: $248,170,600.17
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	138		$59,764,191.82
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$233,675.81
Unscheduled Principal Collection/Reversals		$13,367.92
Liquidations-in-full	27	$12,928,570.02
Net principal Distributed		$13,175,613.75	-$13,175,613.75

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	111		$46,588,578.07

SCHEDULED INTEREST AT MORTGAGE RATE:		$325,635.71

UNSCHEDULED INTEREST AT MORTGAGE RATE:
Unscheduled Interest Collection/Reversals		$0.00
Interest Uncollected on Liquidation		$0.00
Interest Uncollected on Non-Earning Assets		$0.00
Net Unscheduled Interest Distributed		$0.00

OTHER:
Loan Conversion Fees		$0.00
Expense Reimbursements		$0.00
Gain on Liquidations		$0.00
Hazard Insurance Premium Refunds		$0.00
Net Other Distributions		$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
08/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$27,805.21

UNSCHEDULED SERVICING FEES:
Unscheduled Service Fee Collections/Reversals		$0.00
Servicing Fees Uncollected on Liquidation		$0.00
Servicing Fees Uncollected/Non-Earning Assets		$0.00
Net Unscheduled Service Fees Distributed		$0.00

MISCELLANEOUS EXPENSES:		$0.00

NET FUNDS DISTRIBUTED:		$13,473,444.25

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
08/2003 DISTRIBUTION REPORT
SERIES: WAMU 02S3 WEIGHTED AVERAGE PC RATE: 6.33651%
POOL NUMBER: ALL
ISSUE DATE: 05/28/2002
CERTIFICATE BALANCE AT ISSUE: $935,526,459.61
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	576		$249,978,965.10
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$415,946.19
Unscheduled Principal Collection/Reversals		$32,177.28
Liquidations-in-full	110	$50,187,469.14
Net principal Distributed		$50,635,592.61	-$50,635,592.61

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	466		$199,343,372.49

SCHEDULED INTEREST AT MORTGAGE RATE:		$1,436,190.73

UNSCHEDULED INTEREST AT MORTGAGE RATE:
Unscheduled Interest Collection/Reversals		$0.00
Interest Uncollected on Liquidation		$0.00
Interest Uncollected on Non-Earning Assets		$0.00
Net Unscheduled Interest Distributed		$0.00

OTHER:
Loan Conversion Fees		$0.00
Expense Reimbursements		$0.00
Gain on Liquidations		$0.00
Hazard Insurance Premium Refunds		$0.00
Net Other Distributions		$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
08/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$116,196.21

UNSCHEDULED SERVICING FEES:
Unscheduled Service Fee Collections/Reversals		$0.00
Servicing Fees Uncollected on Liquidation		$0.00
Servicing Fees Uncollected/Non-Earning Assets		$0.00
Net Unscheduled Service Fees Distributed		$0.00

MISCELLANEOUS EXPENSES:		$0.00

NET FUNDS DISTRIBUTED:		$51,955,587.13

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003

Distribution by Group
Pool ID		Principal		Interest		Total
Pool - 1864		$37,459,978.86		$1,022,164.02		$38,482,142.88
Pool - 1865		$13,175,613.75		$297,830.50		$13,473,444.25
Aggregate		$50,635,592.61		$1,319,994.52		$51,955,587.13

Number of Loans and Aggregate Principal Balance By Group
Pool ID	Beg Bal	Beg Count	Paid Off / Liq Count	Rem Count	Sched Prin End Bal	Sched Prin	Prin PrePay / Liq	Unsched Prin / Rev	Total Prin
Pool - 1864	$190,214,773.28	438	83	355	$152,754,794.42	$182,270.38	$37,258,899.12	$18,809.36	$37,459,978.86
Pool - 1865	$59,764,191.82	138	27	111	$46,588,578.07	$233,675.81	$12,928,570.02	$13,367.92	$13,175,613.75
Aggregate	$249,978,965.10	576	110	466	$199,343,372.49	$415,946.19	$50,187,469.14	$32,177.28	$50,635,592.61

Delinquency Information by Group
Pool ID	1 Month Count	Sched End Balance	2 Months Count	Sched End Balance	3 Months Count	Sched End Balance	4 Months Count	Sched End Balance
Pool - 1864	8	$3,617,651.88	2	$736,159.00	0	$0.00	0	$0.00
Pool - 1865	2	$823,388.49	1	$303,656.82	0	$0.00	0	$0.00
Aggregate	10	$4,441,040.37	3	$1,039,815.82	0	$0.00	0	$0.00

Foreclosure and REO Information by Group
Pool ID		Foreclosure Count		Sched End Balance		REO Count		Sched End Balance
Pool - 1864		1		$682,486.16		1		$611,262.64
Pool - 1865		0		$0.00		0		$0.00
Aggregate		1		$682,486.16		1		$611,262.64

Aggregate Loss Amounts by Group
Pool ID			Count			Loss Amount
Group 1(1864)			0			$0.00
Group 2(1865)			0			$0.00
Aggregate			0			$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003

INSURANCE RESERVES - Group 1(1864)
Insurance Type	Original Balance	Claims In Progress	Claims Paid	Coverage Adjustments	Coverage Remaining
MPI	$0.00	$0.00	$0.00	$0.00	$0.00
Special Hazard	$0.00	$0.00	$0.00	$0.00	$0.00
Bankruptcy Bond
Single-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$0.00	$0.00	$0.00	$0.00	$0.00

INSURANCE RESERVES - Group 2(1865)
Insurance Type	Original Balance	Claims In Progress	Claims Paid	Coverage Adjustments	Coverage Remaining
MPI	$0.00	$0.00	$0.00	$0.00	$0.00
Special Hazard	$0.00	$0.00	$0.00	$0.00	$0.00
Bankruptcy Bond
Single-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$0.00	$0.00	$0.00	$0.00	$0.00

INSURANCE RESERVES - Aggregate
Insurance Type	Original Balance	Claims In Progress	Claims Paid	Coverage Adjustments	Coverage Remaining
MPI	$0.00	$0.00	$0.00	$0.00	$0.00
Special Hazard	$0.00	$0.00	$0.00	$0.00	$0.00
Bankruptcy Bond
Single-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$0.00	$0.00	$0.00	$0.00	$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.02S3
Distribution Date: 08/25/2003

The Class Principal Balances of each Class of the Class IB1,IB2,IB3,IB4,IB5,IB6 Certificatesimmediately after the principal and interest distribution on 200308 are as follows:

Class			Class Principal Balance
IB1			$10,173,557.56
IB2			$3,729,975.52
IB3			$2,712,619.76
IB4			$1,355,816.51
IB5			$1,017,355.76
IB6			$1,358,651.77
Total			$20,347,976.89
Capitalized items used but not defined herein have the meanings ascribed to them in the Prospectus Supplement.

The Class Principal Balances of each Class of the Class IIB1,IIB2,IIB3,IIB4,IIB5,IIB6 Certificatesimmediately after the principal and interest distribution on 200308 are as follows:

Class			Class Principal Balance
IIB1			$1,762,179.14
IIB2			$352,246.45
IIB3			$352,246.45
IIB4			$234,830.98
IIB5			$117,415.49
IIB6			$236,235.39
Total			$3,055,153.90
Capitalized items used but not defined herein have the meanings ascribed to them in the Prospectus Supplement.

WAMU MORTGAGE PASS THROUGH CERTIFICATES SERIES 2002-S3 8-K