Costco Wholesale Corporation Reports May Sales Results

ISSAQUAH, WA--(Marketwire - June 4, 2009) - Costco Wholesale Corporation ("Costco") (NASDAQ: COST) today reported net sales of $5.47 billion for the month of May, the four weeks ended May 31, 2009, a decrease of five percent from $5.77 billion in the same four-week period last year. Both this year's and last year's four-week periods included 27 days in the U.S. (closed Memorial Day) and Canada (closed Victoria Day).

For the first thirty-nine weeks of its reporting period ended May 31, 2009, the Company reported net sales of $52.15 billion, a decrease of one percent from $52.69 billion during the similar thirty-nine-week period last year.

Comparable sales for the four-week retail-reporting month of May and the thirty-nine-week retail-reporting period of September through May, both ended May 31, 2009, were as follows:

                                4 Weeks         39 Weeks
                                -------         --------
U.S.                              -6%              -1%
International                     -7%             -10%

Total                             -7%              -3%
                                =======         ========

Comparable sales for the four-week and thirty-nine week periods, excluding the negative impacts from gasoline deflation and foreign exchange (primarily in Canada, the United Kingdom and Korea), were as follows:

                                4 Weeks         39 Weeks
                                -------         --------
U.S. (w/o gas deflation)          -1%              +2%
International (w/o Fx)            +7%              +8%

Total                             +1%              +3%
                                =======         ========

Additional discussion of these sales results is available on a pre-recorded telephone message. You can access the recording by dialing 1-800-642-1687 (conference ID 75873421). This recorded message will be available today through 5:00 p.m. (PT) on Friday, June 5, 2009.

Costco currently operates 555 warehouses, including 407 in the United States and Puerto Rico, 77 in Canada, 21 in the United Kingdom, six in Korea, five in Taiwan, eight in Japan and 31 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 an additional six new warehouses and close its two Costco Home locations prior to the end of its 2009 fiscal year, on August 30, 2009.

Certain statements contained in this document and the pre-recorded telephone message 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 and workers' compensation costs), rising costs associated with the acquisition of merchandise (including the direct and indirect effects of the rising cost of petroleum-based products and fuel and energy 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.

Contact Information: CONTACTS: Costco Wholesale Corporation Richard Galanti, 425/313-8203 Bob Nelson, 425/313-8255 Jeff Elliott, 425/313-8264