Costco March Comps Increase 6%

Costco Wholesale Corporation recorded net sales of $5.94 billion for the month of March, representing an increase of 11% from $5.37 billion in the same five-week period last year.

For the first thirty-two weeks of its reporting period ended April 8, 2007, the company reported net sales of $38.11 billion, an increase of 9% from $35.02 billion during the similar thirty-two-week period of the prior year. These year-to-date net sales results include the $224 million adjustment to the sales returns reserve previously reported in the fiscal 2007 second quarter results.

Comparable sales for the 5-week retail-reporting month of March and the 32-week retail-reporting period of September through March are as follows:

 
                                5 Weeks    32 Weeks
                              ----------  ----------

             US                       5%          4%
             International            7%          8%

             Total Company            6%          5%
                              ==========  ==========

This year's five-week period included 34 days of sales compared to 35 days last year, reflecting the timing of Easter. This calendar shift impacted sales negatively by approximately one to two percent.