I Don't Know How She Does It was released for North American audiences on September 16, 2011.
On Rotten Tomatoes, the film has an approval rating of 16% based on 110 reviews, with an average rating of 4/10. The site described the film as " limp comedy with a hopelessly outdated viewpoint on gender, featuring Sarah Jessica Parker in rote Carrie-mode." On Metacritic, the film has a score of 38 out of 100, based on 31 critics, indicating "generally unfavorable reviews". Audiences polled by CinemaScore gave the film an average grade of "B–" on an A+ to F scale.
Sarah Jessica Parker earned a Razzie Award nomination as Worst Actress for her performance in the movie (also for New Year's Eve), but lost to Adam Sandler for his performance in drag in Jack and Jill.
I Don't Know How She Does It opened at #6 on its opening weekend with $4,402,201. It earned $9,662,284 in the United States as well as $20,889,211 internationally for a worldwide total of $30,551,495.