Exhibit 99.1

COSTCO WHOLESALE CORPORATION REPORTS FOURTH QUARTER AND FISCAL YEAR 2010

OPERATING RESULTS AND SEPTEMBER SALES RESULTS

ISSAQUAH, Wash., October 6, 2010 - Costco Wholesale Corporation (Nasdaq: COST) announced today its operating results for the 16 weeks (fourth quarter) and the 52 weeks (fiscal year) ended August 29, 2010, and its September sales results.

Net sales for the fiscal 2010 fourth quarter, the 16 weeks ended August 29, 2010, were $23.59 billion, an increase of eight percent from $21.89 billion in the 16-week fourth quarter of fiscal 2009 ended August 30, 2009. Net sales for the 52-week fiscal year 2010 were $76.25 billion, an increase of nine percent from $69.89 billion in the 52-week fiscal year 2009 ended August 30, 2009.

Comparable sales for the 16-week fiscal fourth quarter and the 52-week fiscal year 2010 were as follows:

	16 Weeks		52 Weeks
U.S.	4	%	4	%
International	14	%	19	%
Total Company	6	%	7	%

Comparable sales for the 16-week and 52-week periods, excluding the positive impacts from gasoline inflation and the strengthening of foreign currencies (primarily in Canada and Korea), were as follows:

	16 Weeks		52 Weeks
U.S.	3	%	2	%
International	8	%	8	%
Total Company	4	%	4	%

Net income for the fourth quarter of fiscal 2010 was $432 million, or $.97 per diluted share, compared to $374 million, or $.85 per diluted share, during the fourth quarter of fiscal 2009.

Net income for fiscal 2010 was $1.30 billion, or $2.92 per diluted share, compared to $1.09 billion, or $2.47 per diluted share, during fiscal year 2009.

For the five-week reporting month of September, ended October 3, 2010, the Company reported net sales of $7.51 billion, an increase of ten percent from $6.84 billion during the similar five-week period of the prior year. This year’s five-week period includes sales from the Company’s Mexico joint venture, as the Company began consolidating its Mexico operations on a prospective basis beginning with its 2011 fiscal year on August 30, 2010, due to the adoption of a new accounting standard. Total sales for the five-week period excluding Mexico sales reflected a seven percent increase over the similar five-week period of the prior year.

Comparable sales for the five-week retail-reporting month of September were as follows:

	5 Weeks
U.S.	2	%
International	14	%
Total Company	5	%

Comparable sales for the five-week period, excluding the positive impacts from gasoline inflation and foreign exchange (primarily in Canada and Korea), were as follows:

	5 Weeks
U.S.	2	%
International	10	%
Total Company	4	%

Costco currently operates 573 warehouses, including 417 in the United States and Puerto Rico, 79 in Canada, 22 in the United Kingdom, seven in Korea, six in Taiwan, nine in Japan, one in Australia and 32 in Mexico. The Company also operates Costco Online, an electronic commerce web site, at www.costco.com and at www.costco.ca in Canada. The Company plans to open up to nine additional warehouses in the first four months of fiscal 2011, prior to the end of calendar year 2010.

A conference call to discuss these fiscal 2010 fourth quarter and year-end operating results is scheduled for 7:00 a.m. (PT) today, October 6, 2010, and is available via a webcast on www.costco.com (click on Investor Relations and “Play Webcast”).

Certain statements contained in this document constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. For these purposes, forward-looking statements are statements that address activities, events, conditions or developments that the Company expects or anticipates may occur in the future. Such forward-looking statements involve risks and uncertainties that may cause actual events, results or performance to differ materially from those indicated by such statements. These risks and uncertainties include, but are not limited to, domestic and international economic conditions, including exchange rates, the effects of competition and regulation, uncertainties in the financial markets, consumer and small business spending patterns and debt levels, conditions affecting the acquisition, development, ownership or use of real estate, actions of vendors, rising costs associated with employees (including health care costs), geopolitical conditions and other risks identified from time to time in the Company’s public statements and reports filed with the Securities and Exchange Commission.

CONTACTS: Costco Wholesale Corporation

Richard Galanti, 425/313-8203, Bob Nelson, 425/313-8255, Jeff Elliott, 425/313-8264

COSTCO WHOLESALE CORPORATION

CONSOLIDATED STATEMENTS OF INCOME

(dollars in millions, except per share data)

(unaudited)

	16 Weeks Ended						52 Weeks Ended
	August 29, 2010			August 30, 2009			August 29, 2010			August 30, 2009
REVENUE
Net sales	$	23,592		$	21,888		$	76,255		$	69,889
Membership fees		533			490			1,691			1,533
Total revenue		24,125			22,378			77,946			71,422
OPERATING EXPENSES
Merchandise costs		21,024			19,512			67,995			62,335
Selling, general and administrative		2,401			2,254			7,840			7,252
Preopening expenses		9			12			26			41
Provision for impaired assets and closing costs, net		3			2			8			17
Operating income		688			598			2,077			1,777
OTHER INCOME (EXPENSE)
Interest expense		(34	)		(33	)		(111	)		(108	)
Interest income and other, net		30			19			88			58
INCOME BEFORE INCOME TAXES		684			584			2,054			1,727
Provision for income taxes		247			206			731			628
Net income including noncontrolling interests		437			378			1,323			1,099
Net income attributable to noncontrolling interests		(5	)		(4	)		(20	)		(13	)
NET INCOME ATTRIBUTABLE TO COSTCO	$	432		$	374		$	1,303		$	1,086
NET INCOME PER COMMON SHARE ATTRIBUTABLE TO COSTCO:
Basic	$	0.99		$	0.86		$	2.97		$	2.50
Diluted	$	0.97		$	0.85		$	2.92		$	2.47
Shares used in calculation (000’s)
Basic		437,071			435,255			438,611			433,988
Diluted		444,289			441,699			445,970			440,454
Dividends per share	$	0.205		$	0.180		$	0.770		$	0.680

COSTCO WHOLESALE CORPORATION

CONDENSED CONSOLIDATED BALANCE SHEETS

(dollars in millions)

(unaudited)

Subject to Reclassifications

	August 29, 2010		August  30, 2009
ASSETS
Cash and cash equivalents	$	3,214	$	3,157
Short-term investments		1,535		570
Receivables, net		884		834
Merchandise inventories		5,638		5,405
Deferred income taxes and other current assets		437		371
Total current assets		11,708		10,337
Property and equipment, net		11,314		10,900
Other assets		793		742
TOTAL ASSETS	$	23,815	$	21,979
LIABILITIES AND EQUITY
Accounts payable	$	5,947	$	5,450
Short-term borrowings and current portion of long-term debt		26		96
Other current liabilities		4,090		3,735
Total current liabilities		10,063		9,281
Long-term debt, excluding current portion		2,141		2,130
Deferred income taxes and other liabilities		681		464
Total liabilities		12,885		11,875
Total Costco stockholders’ equity		10,829		10,024
Noncontrolling interests		101		80
Total equity		10,930		10,104
TOTAL LIABILITIES AND EQUITY	$	23,815	$	21,979