News Release

Costco Wholesale Corporation Reports March Sales Results
Comparable sales for the 5-week and 31-week periods ended April 7, 2002, were as follows:
5 Weeks 31 Weeks -------------- -------------- US 8% 7% International 0% 0% Total Company 7% 6% ============== ==============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 percent.
Costco currently operates 386 warehouses, including 285 in the United States, 60 in Canada, 11 in the United Kingdom, five in Korea, three in Taiwan, two in Japan and 20 in Mexico. The Company also operates Costco Online, an electronic commerce web site, at www.costco.com. The Company plans to open 14 to 16 additional new warehouses (including the relocation of three to four warehouses to larger and better-located facilities) prior to the end of its fiscal year ending September 1, 2002.
CONTACT: Costco Wholesale Corporation Richard Galanti, 425/313-8203 Bob Nelson, 425/313-8255