- California Doubling: Averted with all three films in a way. The first film was set in the fictional Cold River, and the next two films were set in the fictional Mortville. The first film was filmed in Texas, the second film was filmed in Florida (including the newly-opened Universal Studios Florida), and the third film was filmed in Los Angeles.
- Deleted Role: Several characters that never appeared in the second movie are seen in the closing credits.
- Edited for Syndication: On The Hub, there were a few things they edited in both films. Some of the language was a bit toned done in both. Another thing they edited was Junior flipping the bird, Nippy crapping, and of course the Crazy Dance scene.
- Executive Veto: During the "It's My Party" montage, Lucy is sawed in half by the clown. Junior replaces the fake saw with the real saw, which ends up cutting off Lucy's dress, revealing her underwear. The scene was cut as too risqué.
- Harpo Does Something Funny: John Ritter and Gilbert Gottfried were given full reign to ad-lib whenever they wanted.
- The Other Darrin: Junior and Ben were re-cast in the final film.
- Except for Gilbert Gottfried, none of the film cast returned for the animated series. The French dub of the cartoon instead replaced everyone except Junior's child actor.
- Real-Life Relative: John Ritter's real-life wife played Ben Healy's wife in the first movie and his love interest in the second movie.
- What Could Have Been:
- Scott Alexander and Larry Karaszewski originally envisioned the first film as both a black comedy and an adult satire of the then-popular trend in films where cute children teach cynical adults how to love.
- Macaulay Culkin auditioned for the role of Junior.
- Dan Aykroyd, Chevy Chase, Richard Dreyfuss, Steve Martin, Rick Moranis and Kurt Russell were all considered for Little Ben Healy. But Chase turned it down due to him shooting National Lampoon's Christmas Vacation, Martin was busy with My Blue Heaven, Moranis and Aykroyd were too busy doing Ghostbusters II, Dreyfuss and Russell wanted too much money and Russell was busy doing Tango & Cash.
- Christopher Lloyd was supposed to play the Bow Tie Killer but he turned down the role because of his commitments with Back to the Future Part III.
- According to the screenwriters, Problem Child 2 was originally much cruder, so much so that the initial cut received an R rating from the MPAA.
- The studio wanted John Landis to direct this film, but Landis declined as he wasn't interested in directing a kids/family movie. Joe Dante was also approached. But despite showing interest, he turned it down due to conflicts with Gremlins 2: The New Batch. Richard Donner was also considered to direct, but he declined as he was busy in post-production on Lethal Weapon 2.
- The screenwriters tried pitching the movie to several studios including 20th Century Fox, Columbia Pictures and Warner Bros. 20th Century Fox executive Barry Diller hated the script while Columbia and Warner Bros showed no confidence in the film. They eventually convinced Universal Studios to greenlight the film.
- Write What You Know: The screenwriters got the idea for this film from a newspaper article they read, about a couple who sued an adoption agency for giving them a boy with a violent history without informing them beforehand.
- You Look Familiar: Ben Healy's mean wife Flo Healy in Problem Child and his sweet-natured love interest Annie Young in Problem Child 2 are played by the same actress. Oddly, no-one points out the resemblance. Amy Yasbeck, the actress in question was John Ritters real-life wife at the time.
Trivia / Problem Child