WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.03AR8
Distribution Date: 09/25/2003

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
A	92922FAS7	$1,214,965,000.00	$1,194,038,008.73	4.0300000000%	4.0300000000%	$4,009,977.65	$14,287,819.25	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$18,297,796.90	$1,179,750,189.48
X	92922FAT5	$1,214,965,000.00	$1,194,038,008.73	0.2232396022%	0.2232396022%	$222,130.48	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$222,130.48	$1,179,750,189.48
B1	92922FAU2	$13,124,000.00	$13,121,020.31	4.2532396022%	4.2532396022%	$46,505.70	$3,014.11	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$49,519.81	$13,118,006.20
B2	92922FAV0	$9,999,000.00	$9,996,729.81	4.2532396022%	4.2532396022%	$35,432.07	$2,296.41	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$37,728.48	$9,994,433.40
B3	92922FAW8	$4,999,000.00	$4,997,865.02	4.2532396022%	4.2532396022%	$17,714.26	$1,148.09	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$18,862.35	$4,996,716.93
B4	92922FAY4	$1,874,000.00	$1,873,574.52	4.2532396022%	4.2532396022%	$6,640.63	$430.39	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$7,071.02	$1,873,144.13
B5	92922FAZ1	$1,874,000.00	$1,873,574.52	4.2532396022%	4.2532396022%	$6,640.63	$430.39	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$7,071.02	$1,873,144.13
B6	92922FBA5	$3,129,033.60	$3,128,323.18	4.2532396022%	4.2532396022%	$11,087.92	$718.63	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$11,806.55	$3,127,604.55
R	92922FAX6	$100.00	$0.00	0.0000000000%	0.0000000000%	$0.56	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.56	$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		$1,249,964,133.60	$1,229,029,096.09			$4,356,129.91	$14,295,857.27	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$18,651,987.18	$1,214,733,238.82

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.03AR8
Distribution Date: 09/25/2003

Class	Orig Face	Beg Bal	Prin Loss	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
A	$1,214,965,000.00	$1,194,038,008.73	$0.00	$0.00	$14,287,819.25	0.9710157819	$1,179,750,189.48
X	$1,214,965,000.00	$1,194,038,008.73	$0.00	$0.00	$0.00	0.9710157819	$1,179,750,189.48
B1	$13,124,000.00	$13,121,020.31	$0.00	$0.00	$3,014.11	0.9995432947	$13,118,006.20
B2	$9,999,000.00	$9,996,729.81	$0.00	$0.00	$2,296.41	0.9995432943	$9,994,433.40
B3	$4,999,000.00	$4,997,865.02	$0.00	$0.00	$1,148.09	0.9995432947	$4,996,716.93
B4	$1,874,000.00	$1,873,574.52	$0.00	$0.00	$430.39	0.9995432924	$1,873,144.13
B5	$1,874,000.00	$1,873,574.52	$0.00	$0.00	$430.39	0.9995432924	$1,873,144.13
B6	$3,129,033.60	$3,128,323.18	$0.00	$0.00	$718.63	0.9995432935	$3,127,604.55
R	$100.00	$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	$1,249,964,133.60	$1,229,029,096.09	$0.00	$0.00	$14,295,857.27	0.9718144754	$1,214,733,238.82

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.03AR8
Distribution Date: 09/25/2003
PER $1000 DENOMINATION
Class	Orig Face	Beg Bal	Prin Loss	Deferred Interest	Total Prin	End Cert Pct	End Cert Bal
A	$1,214,965,000.00	982.77564270	0.00000000	0.00000000	11.75986078	0.9710157819	971.01578192
X	$1,214,965,000.00	982.77564270	0.00000000	0.00000000	0.00000000	0.9710157819	971.01578192
B1	$13,124,000.00	999.77295870	0.00000000	0.00000000	0.22966397	0.9995432947	999.54329473
B2	$9,999,000.00	999.77295830	0.00000000	0.00000000	0.22966397	0.9995432943	999.54329433
B3	$4,999,000.00	999.77295859	0.00000000	0.00000000	0.22966393	0.9995432947	999.54329466
B4	$1,874,000.00	999.77295624	0.00000000	0.00000000	0.22966382	0.9995432924	999.54329242
B5	$1,874,000.00	999.77295624	0.00000000	0.00000000	0.22966382	0.9995432924	999.54329242
B6	$3,129,033.60	999.77295865	0.00000000	0.00000000	0.22966516	0.9995432935	999.54329349
R	$100.00	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.03AR8
Distribution Date: 09/25/2003

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
A	$1,214,965,000.00	4.0300000000%	4.0300000000%	$1,194,038,008.73	$4,009,977.65	$0.00	$0.00	$0.00	$4,009,977.65
X	$1,214,965,000.00	0.2232396022%	0.2232396022%	$1,194,038,008.73	$222,130.48	$0.00	$0.00	$0.00	$222,130.48
B1	$13,124,000.00	4.2532396022%	4.2532396022%	$13,121,020.31	$46,505.70	$0.00	$0.00	$0.00	$46,505.70
B2	$9,999,000.00	4.2532396022%	4.2532396022%	$9,996,729.81	$35,432.07	$0.00	$0.00	$0.00	$35,432.07
B3	$4,999,000.00	4.2532396022%	4.2532396022%	$4,997,865.02	$17,714.26	$0.00	$0.00	$0.00	$17,714.26
B4	$1,874,000.00	4.2532396022%	4.2532396022%	$1,873,574.52	$6,640.63	$0.00	$0.00	$0.00	$6,640.63
B5	$1,874,000.00	4.2532396022%	4.2532396022%	$1,873,574.52	$6,640.63	$0.00	$0.00	$0.00	$6,640.63
B6	$3,129,033.60	4.2532396022%	4.2532396022%	$3,128,323.18	$11,087.92	$0.00	$0.00	$0.00	$11,087.92
R	$100.00	0.0000000000%	0.0000000000%	$0.00	$0.56	$0.00	$0.00	$0.00	$0.56
R_SYN	$0.00	0.0000000000%	0.0000000000%	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
Total	$1,249,964,133.60			$1,229,029,096.09	$4,356,129.91	$0.00	$0.00	$0.00	$4,356,129.91

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.03AR8
Distribution Date: 09/25/2003
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
A	$1,214,965,000.00	4.0300000000%	4.0300000000%	982.77564270	3.30048820	0.00000000	0.00000000	0.00000000	3.30048820
X	$1,214,965,000.00	0.2232396022%	0.2232396022%	982.77564270	0.18282871	0.00000000	0.00000000	0.00000000	0.18282871
B1	$13,124,000.00	4.2532396022%	4.2532396022%	999.77295870	3.54356141	0.00000000	0.00000000	0.00000000	3.54356141
B2	$9,999,000.00	4.2532396022%	4.2532396022%	999.77295830	3.54356136	0.00000000	0.00000000	0.00000000	3.54356136
B3	$4,999,000.00	4.2532396022%	4.2532396022%	999.77295859	3.54356071	0.00000000	0.00000000	0.00000000	3.54356071
B4	$1,874,000.00	4.2532396022%	4.2532396022%	999.77295624	3.54355923	0.00000000	0.00000000	0.00000000	3.54355923
B5	$1,874,000.00	4.2532396022%	4.2532396022%	999.77295624	3.54355923	0.00000000	0.00000000	0.00000000	3.54355923
B6	$3,129,033.60	4.2532396022%	4.2532396022%	999.77295865	3.54356054	0.00000000	0.00000000	0.00000000	3.54356054
R	$100.00	0.0000000000%	0.0000000000%	0.00000000	5.60000000	0.00000000	0.00000000	0.00000000	5.60000000
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
09/2003 DISTRIBUTION REPORT
SERIES: WAMU 03AR8 WEIGHTED AVERAGE PC RATE: 4.25324%
POOL NUMBER: 2156
ISSUE DATE: 07/25/2003
CERTIFICATE BALANCE AT ISSUE: $1,249,964,133.60
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	1899		$1,229,029,096.09
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$282,327.78
Unscheduled Principal Collection/Reversals		$3,257,172.66
Liquidations-in-full	13	$10,756,356.83
Net principal Distributed		$14,295,857.27	-$14,295,857.27

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	1886		$1,214,733,238.82

SCHEDULED INTEREST AT MORTGAGE RATE:		$4,791,411.16

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
09/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$435,281.25

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:		$18,651,987.18

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
MASTER SERVICING
MORTGAGE PASS-THROUGH CERTIFICATES
09/2003 DISTRIBUTION REPORT
SERIES: WAMU 03AR8 WEIGHTED AVERAGE PC RATE: 4.25324%
POOL NUMBER: ALL
ISSUE DATE: 07/25/2003
CERTIFICATE BALANCE AT ISSUE: $1,249,964,133.60
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
BALANCES FROM LAST FISCAL MONTH-END:	1899		$1,229,029,096.09
PRINCIPAL POOL COLLECTION(S):
Scheduled Principal Collection Due Current Month		$282,327.78
Unscheduled Principal Collection/Reversals		$3,257,172.66
Liquidations-in-full	13	$10,756,356.83
Net principal Distributed		$14,295,857.27	-$14,295,857.27

CAPITAL LOSS (PRINCIPAL WRITTEN OFF):			$0.00

BALANCE CURRENT FISCAL MONTH-END:	1886		$1,214,733,238.82

SCHEDULED INTEREST AT MORTGAGE RATE:		$4,791,411.16

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
09/2003 DISTRIBUTION REPORT
	TOTAL NUMBER OF MORTAGES	CERTIFICATE ACCOUNT ACTIVITY (@ PCRATE)	CERTIFICATE BALANCE OUTSTANDING
SCHEDULED SERVICING FEE EXPENSES:		$435,281.25

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:		$18,651,987.18

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.03AR8
Distribution Date: 09/25/2003

Distribution by Group
Pool ID		Principal		Interest		Total
Pool - 2156		$14,295,857.27		$4,356,129.91		$18,651,987.18
Aggregate		$14,295,857.27		$4,356,129.91		$18,651,987.18

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 - 2156	$1,229,029,096.09	1899	13	1886	$1,214,733,238.82	$282,327.78	$10,756,356.83	$3,257,172.66	$14,295,857.27
Aggregate	$1,229,029,096.09	1899	13	1886	$1,214,733,238.82	$282,327.78	$10,756,356.83	$3,257,172.66	$14,295,857.27

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 - 2156	20	$12,196,533.62	0	$0.00	0	$0.00	0	$0.00
Aggregate	20	$12,196,533.62	0	$0.00	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 - 2156		0		$0.00		0		$0.00
Aggregate		0		$0.00		0		$0.00

Aggregate Loss Amounts by Group
Pool ID			Count			Loss Amount
Group 1(2156)			0			$0.00
Aggregate			0			$0.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.03AR8
Distribution Date: 09/25/2003

INSURANCE RESERVES - Group 1(2156)
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	$17,873,026.00	$0.00	$0.00	$0.00	$17,873,026.00
Bankruptcy Bond
Single-Units	$148,203.00	$0.00	$0.00	$0.00	$148,203.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$24,999,282.00	$0.00	$0.00	$0.00	$24,999,282.00

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	$17,873,026.00	$0.00	$0.00	$0.00	$17,873,026.00
Bankruptcy Bond
Single-Units	$148,203.00	$0.00	$0.00	$0.00	$148,203.00
Multi-Units	$0.00	$0.00	$0.00	$0.00	$0.00
Mortgage Repurchase	$24,999,282.00	$0.00	$0.00	$0.00	$24,999,282.00

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.03AR8
Distribution Date: 09/25/2003

The Class Principal Balances of each Class of the Class B1,B2,B3,B4,B5,B6 Certificatesimmediately after the principal and interest distribution on 200309 are as follows:

Class			Class Principal Balance
B1			$13,118,006.20
B2			$9,994,433.40
B3			$4,996,716.93
B4			$1,873,144.13
B5			$1,873,144.13
B6			$3,127,604.55
Total			$34,983,049.34
Capitalized items used but not defined herein have the meanings ascribed to them in the Prospectus Supplement.

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.
Series: WAMU.03AR8
Distribution Date: 09/25/2003

Aggregate ARM Information by Group
Pool ID	Netwac	Margin
Pool - 2156	4.25324%	2.32523%
Aggregate	4.25324%	2.32523%

WAMU MORTGAGE PASS THROUGH CER SER 2003-AR8 8-K