Arnold Schwarzenegger had a few conditions before accepting the role of John Kimble; he wanted Ivan Reitman to direct the film, he wanted a physical fitness theme, and he and Reitman wanted broken homes, child abuse and family life written into the script.
Owning a pet ferret, like Kimble does, is illegal in California - a ban which former governor Arnold Schwarzenegger supported, fortunately this film is set (and filmed partially) in Astoria Oregon where it is perfectly legal.
When Kimble carries Phoebe into the motel, he says two short sentences in German (the first time Arnie can be heard speaking his native language in a movie). For interest, these mean: "That makes me stinking mad. Now I'm mad." The second time he spoke German wouldn't be until Escape Plan (2013).
Arnold Schwarzenegger worked with Pamela Reed again in the movie Junior (1994) which was also directed by Ivan Reitman . Reed portrayed a pregnant woman with a big appetite, quite similar to her character in this movie. He also worked with Danny DeVito in Junior (1994), a candidate for the role of John Kimble, but was not given the part due to his height.
Arnold Schwarzenegger speculates that the film could have grossed an extra $25 million if it were less violent. But Ivan Reitman felt like the violence "had to be there or the film would just beter out at the end."
On April Fool's Day 2012, as a prank, it was announced that the film was selected for a release on DVD and Blu-ray Disc as part of the Criterion Collection, a video-distribution company dedicated to the release of "important classic and contemporary films". It was said to be selected as important in part because of its genre-revisionist use of both the policier and family comedy genres in the same film.
During the scene when Kimbal goes over to Joyce's house for dinner, in Dominic's room you can see that he has Ghostbusters sheets on his bed. Both Ghostbusters and this film were directed by Ivan Reitman.
Pamela Reed, who plays Phoebe in this movie, was in the movie The Right Stuff playing Trudy Cooper, wife of Gordon Cooper. Odette Annable, who plays Rosa, one of the kindergarteners in this movie, played Trudy Cooper in The Astronaut Wives Club.
In the "Police School" scene Kimble says to the class that "It's time now to turn this mush into muscle". The line is a humorous poke at Schwarzenegger himself: he was a champion bodybuilder prior to becoming an actor and politician, where began weight training at the age of 15 and won the Mr. Universe title at the age of 20 and went on to win the Mr. Olympia contest several times.
The trivia item below may give away important plot points.
Throughout the entire movie Kimball continues to assure people that the ferret doesn't bite. Ironically, at the climax of the movie, Dominic is saved when the ferret crawls out of his jacket and bites Crisp in the neck.