- The hotel that Lloyd and Harry stay at when they get the money is the Stanley Hotel in Estes Park, Colorado. This hotel was also used as The Overlook in "Shining, The" (1997) (mini).
- Jim Carrey takes out his cap for his chipped tooth for the movie.
- Cam Neely who played Sea Bass in Dumb & Dumber also played Lieutenant Sea Bass in Me Myself & Irene (2000) which also starred Jim Carrey.
- Jim Carrey refused to shoot an alternate ending of Harry and Lloyd getting on the bus with the Tropicana girls.
- The "most annoying sound in the world" was ad-libbed by Jim Carrey during filming.
- Production was shut down in Salt Lake City for a week when Jim Carrey had surgery for a gallstone.
- After the guys pull the bill-paying stunt on Sea Bass, Harold asks Lloyd where he got that idea. Lloyd tells him that he saw it in a movie. This is a reference to the movie Something Wild (1986) in which Jeff Daniels does the same thing to Ray Liotta.