Costco October Comp Store Sales Up 8%

Costco Wholesale Corporation reported net sales of $3.79 billion for the four weeks ended October 31, 2004, an increase of 11 percent from $3.42 billion in the same four-week period of the prior fiscal year.

For the first 9 weeks of its 2005 fiscal year ended October 31, 2004, the Company reported net sales of $8.32 billion, an increase of 11 percent from $7.49 billion during the similar 9-week period of the prior fiscal year.

Comparable sales for the 4-week and 9-week periods ended October 31, 2004, were as follows:

                       4 Weeks        9 Weeks
                     ------------   ------------
US                             7%             8%
International                  9%             9%

Total Company                  8%             8%
                     ============   ============

Reported net sales were reduced by the implementation of Emerging Issues Task Force Issue No. 03-10 (“EITF 03-10”), “Application of Issue No. 02-16 by Resellers to Sales Incentives Offered to Consumers by Manufacturers,” which was effective at the beginning of the Company's fiscal 2004 third quarter, February 16, 2004. Had sales for the 4-week and 9-week periods last year been reported under EITF 03-10, total Company reported net sales increases would have been 11 percent and 12 percent, respectively, and total Company comparable sales increases would have been 8 percent and 8 percent, respectively.