The premise came about when John Hughes told Lauren Shuler Donner about a disastrous experience he had looking after his two children while his wife was away. Donner found it hilarious. Hughes asked if that could make a good movie, and Donner replied that "it sure sounds funny to me". Hughes wrote the film, and flew to Los Angeles to re-write the script with Donner.
Jack is the only male shopper in the entire grocery store.
While Lauren Shuler Donner talked to her agent friend Laurie Perlman, Perlman told her about Michael Keaton, "this guy who is really funny" who she represented. After meeting Keaton and seeing Night Shift (1982), Donner decided to send him the script.