Originally, the "Seymour Butts" joke was suppose to be a "Peter Fitz" joke. Josh was going to tell Tony that the Chipmunk Bunk snack horde belongs to "Peter Fitz." Then, Tony asks, "Who's Peter Fitz?" Josh answers with, "Anyone's Peter Fitz if you push hard enough". The joke was changed to "Seymour Butts" to be more family friendly.
While Ben Stiller played the parts of both Tony Perkins and his father, the Bushkins were played by his actual parents, Jerry Stiller and Anne Meara.
As part of his first date with his eventual wife, Judd Apatow tried to impress Leslie Mann by showing her this film.
As the kids are getting off the Camp Hope bus when first arriving, you can see the Max. Capacity is 25. The 25 is scratched over and a "23" is written above it.
While filming the scene where the kids have a party after locking up Tony Perkins and restoring the camp back to the way it was, Aaron Schwartz (Gerry) injured his arm. His cast had to be hidden in scenes featuring him.