- Actor-Inspired Element:
- Channel Hop: PolyGram Filmed Entertainment and Working Title Films (who financed the film) didn't have full US distribution. They tried selling the film to a variety of studios including TriStar Pictures, Metro-Goldwyn-Mayer, Orion Pictures and 20th Century Fox, all of whom turned it down. Ultimately, New Line Cinema picked up the theatrical rights to the movie.
- Deleted Scene: New Line Cinema had asked director Ate De Jong to cut out some of the gross-out humor such as a shot where Fred spits on Lizzie's head and a scene where Fred flicks snot into Polly's coffee. These scenes have since resurfaced on the film's 25th Anniversary Blu-Ray release.
- No Export for You: Some parts of Europe, the UK in particular, managed to get a Blu-Ray release but in the U.S., it's currently only available in Digital HD; plus the U.S. DVD has long been out-of-print.
- Real-Life Relative: Grandma Bunce is played by the director's mother. For the scene where she gets paint thrown on her, yogurt was used. Weeks later, she said she still found some yogurt in her ears.
- Star-Derailing Role: Cates was in exactly three more films after this one, none of them hits or remotely memorable. It didn't exactly make Rik Mayall a film star across the pond either (though he did go on to be in Harry Potter and the Philosopher's Stone... except he was cut from the finished product).
- Stillborn Franchise: Shortly after the film's release, Carlos Davis and Anthony Fingleton and producer Paul Webster began working with PolyGram, Working Title Films and New Line Cinema on a sequel, but Rik Mayall declined to return. So the sequel was reworked with a then-unknown Jim Carrey in the role. But this version was scrapped both due to PolyGram experiencing financial difficulties and Carrey had signed on to do Ace Ventura: Pet Detective instead. In the early 2000s, Mayall worked with both Fingleton and Davis on a proper sequel with Working Title producing and financing the budget and Focus Features distributing. Though this sequel would also not materialize due to Mayall's declining health.
- Uncredited Role: Bridget Fonda did an uncredited cameo in favor of her friend, Phoebe Cates.
- What Could Have Been:
- The script was originally offered to Tim Burton, but he declined to direct.
- Rosanna Arquette was originally set to play Lizzie. Molly Ringwald, Julia Roberts, Winona Ryder and Lea Thompson were also considered.
- Robin Williams was offered the role of Fred, but he was busy with Hook. The writers originally envisioned John Cleese in the role.
- Alec Baldwin, Jeff Goldblum, Jeffrey Jones and Rick Moranis were considered for Charles.
- Josh Brolin, Michael J. Fox, Anthony Michael Hall, Matthew Modine, Keanu Reeves, and Charlie Sheen were considered for Mickey Bunce.
- Geena Davis was considered for Janie.
- Phoebe Cates' husband Kevin Kline was meant to have a cameo in the film, but it never happened.
- In 2009, there were plans for a remake starring Russell Brand, but it was abandoned following the failure of the Arthur remake.
- Write What You Know: The scene where Polly tapes up the jack-in-the-box containing Fred was based off an actual incident that happened to a friend of co-writer/executive producer Carlos Davis named Steve Burnette. Burnette's mother Gloria had an imaginary friend when she was a little girl. But the girl's mother couldn't stand the fact that her daughter had an imaginary friend. It finally got to the point where Gloria's mother took her imaginary friend and flushed it down the toilet. This incident traumatized her for three years.
- Written By Castmember: Carrie Fisher rewrote some of her dialogue.
Trivia / Drop Dead Fred