Nadia's first scene was actually shot in downtown LA, not New York. The World Trade Center towers were composited into the skyline. Yellow cabs and hot dog vendors were added for effect.
Adam Herz, the writer of this film, wrote the screenplay with numerous references to the University of Michigan (his own alma mater). He also included Michigan's fight song, "Hail to the Victors", in the movie. However, the university did not approve use of its name, due to the adult nature of the film. Herz had to omit any reference to the school.
The movie originally included scenes featuring Stifler's dad (played by Chris Penn). These were removed after negative reaction in test screenings. Also missing from the theatrical release is a scene showing the band camp leader with a rash around his mouth, the morning after having played the trumpet that was inserted into Jim's ass.
In the scene when Alyson Hannigan (Michelle) is "breaking up" with Jim, her hair is styled differently than normal. This is because she was shooting an episode of Buffy the Vampire Slayer and she ran over to the set during a break.
The classroom used in the opening scene where Chris Ostreicher (Chris Klein} and Steve Stifler (Seann William Scott) are getting ready to take a final exam is the same one used in Old School when Frank Ricard (Will Ferrell) is getting beaten up by Dean "Cheese" Gordon Pritchard (Jeremy Piven).
Eddie Kaye Thomas was laughing so hard at Seann William Scott's antics during the lesbian scene that he had to be cut out of a lot of the shots. This is why these scenes contain a lot of shots of just Stifler and Jim, even though Finch is supposed to be standing right next to them.
The band 3 Doors Down recorded an alternate version of their song "Be Like That" for the soundtrack. The first 2 lines were different than the version on their album "The Better Life".