- Fake German: Werner and Hans Klopek are played American actors Henry Gibson and Courtney Gaines, respectively.
- Harpo Does Something Funny:
- The part where Ray lifts himself into the ambulance and complains was ab-libbed by Tom Hanks himself; originally he was just gonna be lifted in normally.
- Rick Ducommun, a stand-up comedian, was encouraged to improvise a lot of lines, to add to his frantic character. Him talking about Satanism in Ray's basement was one bit that was almost entirely improvised.
- Hey, It's That Place!: The set for this movie, Colonial Street at Universal Studios, would later become Wisteria Lane of Desperate Housewives. While all of the houses have appeared in various TV shows and films since, perhaps most recognizable was the Butlers', which was also the house of The Munsters.
- Hostility on the Set:
- Missing Trailer Scene: Theatrical and television trailers show some deleted and extended scenes; Ray cooking at the metal barbecue and accidentally setting it on fire. Shot of Art sitting somewhere outside and mentioning Klopek's name. Shot of Dr. Klopek saying his name, it seems like this shot was in ending of the movie. Ray, Ricky, Walter, and Bonnie all standing by a ladder which leads to someone's roof and Ray saying "I think we're overreacting", by their clothes, it looks like it's from the scene where they break into Walter's house. Ray telling Carol that someone thinks that "the Klopeks are evil incarnate." Ricky helping Art out when he falls over the fence after running from Klopek's dog. Shot of Ricky saying "God, I love this street" which is not from the same scene where he says it in the movie. Reportedly, more scenes were deleted and some extra scenes are said to be included in old television versions of the movie.
- Release Date Change: The film was originally slated for a Christmas 1988 release but due to reshoots, the film was pushed back to February 1989. By that time, Tom Hanks would be nominated for an Oscar for Big.
- Throw It In!:
- Rumsfield ripping the Klopeks' wallpaper was a complete accident by Bruce Dern; he was only meant to tug it a bit, but Joe Dante found it hilarious and kept it.
- Because of the Writer's Guild strike during filming, no official script changes were permitted. As such, much of the film (such as Ray and Carol playing Jeopardy, Art's "Satan is good. Satan is our pal" line, and Ray hurling himself and a stretcher into the ambulance) were ad libbed.
- Wag the Director: After Tom Hanks accepted the role in the film, he was very adamant that he shouldn't have a son in the film and fought to have Cory Danzinger's part written out completely according to Joe Dante. Hanks felt that he shouldn't have been playing a Fred MacMurray type but a more contemporary husband to Carrie Fisher.
- What Could Have Been: The first version of the movie had the Klopeks killing Ray and getting away with it. After this ending, and another one where the Klopeks are completely innocent, tested poorly, the compromise ending where the Klopeks are serial killers but fail to kill Ray worked much better.
- Write What You Know: Screenwriter Dana Olsen based this after weird experiences he had with neighbors growing up. The ice cream murderer story was also recalled after an incident he read about where a local librarian killed his family, then himself.
Trivia / The 'Burbs