Trivia / Innerspace

  • Actor Allusion / Creator In-Joke: William Schallert was cast as Jack's doctor as an in-joke since he had played a doctor in The Incredible Shrinking Man (1957).
  • Acting for Two: Robert Picardo playing Jack!Cowboy and the Cowboy. When Jack!Cowboy comes out of the bathroom after his face is changed you'll see him walk off the left of the screen. A double then steps back in with their back to the camera as a freaked out Lydia climbs across the bed and goes into the bathroom finding the Cowboy still passed out in the bathtub. When he moved off screen and the double took over, he had to rush to change, putting put on a different wig and getting into the bathtub via a false wall. It's all one shot.
  • Cast the Expert: The lab workers seen during the scene where Dennis Quaid is about to be miniaturized were in fact real laboratory workers, as actors would not have been suitable to performing what real lab rats do.
  • Playing Against Type: Mr. Igoe is a calm, collected bad guy who never speaks, the complete opposite of Vernon Wells' previous roles as Wez and Bennett.
  • Retroactive Recognition: The Cowboy is played by Robert Picardo, of Star Trek: Voyager and Stargate SG-1 fame, well before he got either of those parts.
  • Romance on the Set: Dennis Quaid and Meg Ryan fell in love after meeting each other on the set of this film, and they married from 1991 to 2000.
  • What Could Have Been:
    • The original script was darker and less comedic. For instance, during the raid on Vectorscope, the robbers line the scientists up against the wall and shoot them instead of just using knockout gas. Mr. Igoe has lines and is revealed at the end to be an android built by Dr. Canker. Also, the climax was different, involving a helicopter chase across the San Francisco bay.
    • Mel Gibson and Robin Williams were both considered for the role of Jack.