When I Grow Up by The Pussycat Dolls was a major international hit and one of the group’s most iconic singles. In the United States, it debuted at number 76 on the Billboard Hot 100 and climbed to a peak of number nine, becoming their fourth and final top-ten single. The song also topped the Hot Dance Club Play chart and sold over 2.1 million digital downloads, making the group the first all-female act to have three singles exceed two million in digital sales.