Production nearly stopped towards the end of shooting due to Christopher Pettiet's drug addiction, which was starting to get out of control. The producers cut a few of his scenes to keep the film on schedule.
In one of the earlier script drafts, the babysitter's death was supposed to be a more elaborate story line: the Crandell children were all suspects, and they all had their reasons to kill her. Although certain scenes were scaled down, elements of their motives remain in the final cut of the film: Walter having to do a book report, Melissa forced to wear a dress, Zack losing Cynthia.
When the movie was released on video, it had a contest in which participants would answer a number of questions about the movie related to movie trivia, as well as rating various actors' performances. The winner, whose answers matched up the best with an official set, would win the babysitter's car (which stolen by the drag queens).
Keith Coogan was told he was too old to play 15-year-old Kenny. He was 20, a couple years older than his co-star Christina Applegate. He came back to the audition in "stoner apparel" and a wig, and got the part.
Keith Coogan is the grandson of Jackie Coogan, Uncle Fester on The Adams Family. Jackie Coogan was also the impetus for Coogan's Law, a law which protects child actors from being exploited by unethical parents, agents and show business producers. The law was passed when Coogan discovered, at age 21, after years of working in showbusiness, that his bank account had been completely depleted. All the money he had earned doing movies as a child were taken by his mother, who stated, unapologetically, "Any money Jackie made prior to the age of 21 is legally ours, we never promised him otherwise".
John Landis was the first choice to direct this film. But he turned it down as the story didn't interest him. John Hughes was also asked to direct, but he turned it down because he only directed scripts that he wrote himself. Hughes was also trying to distance himself away from working on teen movies. Joe Dante, Richard Donner, and Joel Schumacher also turned it down as well.