Costco Wholesale Corporation operates an international chain of membership warehouses mainly under the Costco Wholesale's name, that carry quality, brand name merchandise at substantially lower prices than are typically found at conventional wholesale or retail sources. The warehouses are designed to help small-to-medium-sized businesses reduce costs in purchasing for resale and for everyday business use. Individuals may also purchase for their personal needs.

Costco's warehouses present one of the largest and most exclusive product category selections to be found under a single roof. Categories may include groceries, candy, appliances, television and media, automotive supplies, tires, toys, hardware, sporting goods, jewelry, watches, cameras, books, housewares, apparel, health and beauty aids, tobacco, furniture, office supplies and office equipment. Costco is known for carrying top quality national and regional brands, with 100% satisfaction guaranteed, at prices consistently below traditional wholesale or retail outlets.

Members can also shop for private label Kirkland Signature products, designed to be of equal or better quality than national brands, including juice, cookies, coffee, housewares, luggage, clothing and detergent. The Company also operates self-service gasoline stations at a number of its U.S. and Canadian locations.

Costco Taiwan is a membership based warehouse club and offers two types of membership: Business and Gold Star (individual).