The scene where Andy has his chest hair removed required five cameras set up for the shot. Steve Carell's chest hair was actually ripped out in the scene. Carell had told director Judd Apatow just before shooting the scene, "It has to be real. It won't be as funny if it's mocked up, or if it's special effect. You have to see that this is really happening." For obvious reasons, the scene had to be done in one shot.
According to Seth Rogen, Steve Carell was so nervous that the film would be shut down by the studio that he had the writers prepare a back-up version of the script that didn't contain a single word of profanity.
When Catherine Keener was cast, Steve Carell told Judd Apatow that her casting had legitimized the film's credibility.