The increase extends Costco's run as one of the stronger retailers in the slow economy. Shoppers have flocked to its stores for deals on basics and more recently for housewares and other discretionary purchases.
Costco, based in Issaquah, Wash., said Wednesday that it earned $348 million, or 79 cents per share, for the period ended Feb. 13. That's up from $299 million, or 67 cents per share, a year ago.
The results met the expectations of analysts polled by FactSet.
Revenue climbed 11 percent to $20.88 billion from $18.74 billion, topping Wall Street's $20.4 billion estimate.
Sales at wholesale clubs open at least a year increased 7 percent. The figure rose 12 percent internationally and 5 percent in the U.S.
This metric is a key gauge of a retailer's health because it excludes stores that open or close during the year.
Taking out the impact of increasing gasoline prices and strengthening foreign currencies, sales at wholesale clubs open at least a year climbed 4 percent. International results rose 8 percent and U.S. results increased 3 percent.
When excluding higher gas prices and strengthening foreign currencies, sales at warehouse clubs open at least a year increased 5 percent. International results rose 7 percent, with the U.S. metric up 4 percent.
For the full year, Costco reported its net income rose 17 percent to $660 million, or $1.49 per share, compared with $565 million, or $1.27 per share, a year earlier.
Annual revenue increased to $40.11 billion from $36.04 billion.
Rival BJ's Wholesale Club Inc. also is expected to report its fourth-quarter results on Wednesday.
Costco runs 581 stores, including 424 in the U.S. and Puerto Rico, 80 in Canada, 22 in the U.K., seven in Korea, six in Taiwan, nine in Japan, one in Australia and 32 in Mexico.