Debut theatrical feature film directed by Joel Schumacher. In his his 2002 autobiography "I Like it Better when You're Funny",Charles Grodin recounts Shumacher once saying "I'm giving directions to Lily Tomlin and Charles Grodin, and they're listening to me!"
John Landis was the original director of the project. In his version, the movie would have ended with the heroine giving a speech in Washington, D.C. when she was less than a foot tall. Universal Pictures wanted the budget scaled back from $30 million to $10 million, so the screenplay was rewritten and Landis dropped out and wrote directed the cult classic An American Werewolf in London (1981) instead.
The character, neighbor Judith Beasley played by Lily Tomlin was derived from one of Tomlin's live stand-up shows.
The name of the medical facility where Lily Tomlin got assessed for shrinking was "The Kleinman Institute". "Klein" is the German / Dutch word for "small".
Robert Blalack's tests exist of Lily Tomlin in various scenes that were shot for the movie in the 3D format, which was having a resurgence of interest in the United States at the time. However, the movie was produced and released in 2D.