Weitz’ early career involved many collaborations with his brother. Some of the work they have done as screenwriters has been both credited and uncredited.
Weitz began his film career as a co-writer on the 1998 animated film Antz. He followed this with work on various sitcoms such as Off Centre and the 1998 revival of the 1977 series Fantasy Island. In 1999, he and Chris directed and produced American Pie, which was written by Adam Herz, and became a major box office success. Weitz returned as executive producer on the film’s two theatrical sequels.
In 2002, the Weitz brothers co-wrote and co-directed About a Boy, the Hugh Grant film based on the book by Nick Hornby. The film was originally set up at New Line Cinema with Robert De Niro producing, and the main character as an American. The brothers felt that it was important that the character is British. Inspiration came from the film The Apartment (1960). They were nominated for an Academy Award for Best Adapted Screenplay.
Weitz has written and directed the well-received romantic comedy In Good Company and the political satire American Dreamz, which faced mixed reviews. Additional writing credits include the television show Cracking Up.
He has also directed an adaptation of Darren Shan’s young adult novel Cirque du Freak called The Vampire’s Assistant. He directed the film Little Fockers (2010), the sequel to Meet the Parents and Meet the Fockers.
Subsequently he wrote and directed Being Flynn, an adaptation of Nick Flynn’s memoir Another Bullshit Night in Suck City, starring Robert De Niro. Weitz said he worked collaboratively with Flynn to translate the dense original source material into its film adaptation.
Weitz also directed the movie Admission, starring Tina Fey.