Costco May Comp Store Sales Increase 16%

Costco Wholesale Corporation reported net sales of $3.80 billion for the four weeks ended May 30, 2004, an increase of 19% from $3.20 billion in the same four-week period of the prior fiscal year.

This year's four-week period included 28 days of sales compared to 27 days last year, reflecting the timing of Memorial Day. This calendar shift impacted sales positively by approximately 3 percent.

For the first 39 weeks of its 2004 fiscal year ended May 30, 2004, the Company reported net sales of $35.15 billion, an increase of 15 percent from $30.67 billion during the similar 39-week period of the prior fiscal year.

Comparable sales for the 4-week and 39-week periods ended May 30, 2004, were as follows:

                       4 Weeks        39 Weeks
                     ------------   ------------
US                            18%            10%
International                  8%            17%

Total Company                 16%            12%
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