Jack Nicholson had director John Landis fly out to his home in Colorado and drive through a snowstorm just to tell him he was not interested in the role of Ed Okin.
Airport scenes in this film (and Coming to America (1988)) have a call over the PA system for a Mr. Frank Ozkerwitz to pick up a white courtesy telephone. This is a reference to Frank Oz, who makes an appearance in many of John Landis' films, although his real last name is Oznowicz.
Jack Nicholson was offered the role of Ed Okin, but turned it down. He told John Landis, "I like it and I like you. But this guy doesn't really do anything. The audience likes the leading man to take action."
John Landis wanted Gene Hackman to play Jeff Goldblum's role, after Jack Nicholson turned it down. Gene Hackman agreed to do it, but Universal thought that he wasn't a big enough box-office draw, because he'd had a couple of box office failures at the time.
John Landis had cast Jamie Lee Curtis for the role of Diana after she had previously appeared in another Landis film Trading Places (1983). However, weeks before shooting she backed out to do Perfect (1985) with John Travolta instead.
John Landis: [filmmakers] John Landis' first film to feature his trademark array of cameos from other filmmakers. In the case of this film, it has been speculated that this was a show of support, in the wake of the fatal accident that occurred while Landis was directing his segment of Twilight Zone: The Movie (1983). This was his first film after the accident.
John Landis: [See You Next Wednesday] Appears on two posters in the office where Ed and Diana make the phone call.