Development
In 1986, Harry F. Saint's Memoirs of an Invisible Man was still unfinished when Hollywood agent William Morris gave it to Chevy Chase to read. The actor instantly got interested, which led to a bidding war among studios. Warner Bros. Pictures paid $1.35 million for the film rights.
William Goldman was assigned to write the screenplay in the mid-1980s, by which time Ivan Reitman was attached to direct. It was Goldman's first screenplay after what he called his "leper" period when he was in no demand to write scripts; he attributes his comeback to being represented by CAA.
The project was largely a vanity project shepherded by Chase through the studio. (The film is billed as "A Cornelius Production": Cornelius is Chevy Chase's real first name.) He wanted to make a film about the loneliness of invisibility, intending the film to be a bridge into less comedic roles. Goldman did three drafts of the script and Warners was prepared to greenlight the film. However Chase was unhappy with the script. Reitman wanted to proceed with the script, but the studio backed Chase, and Reitman left the project.
Goldman also left the project, reportedly saying to Chase, "I'm sorry, but I'm too old and too rich to put up with this shit." (Goldman later said that he had no memory of saying this but had read in a magazine that he had, adding "Wouldn't that be neat if it was me...?") He also said that Mark Canton, head of the studio, did not pay the writer for all his work, causing Goldman to initiate a lawsuit against them.
Chase found Goldman's script too comedic—"Clark Griswold becoming invisible"—and sought screenwriters to rework it, reportedly to do something "more serious, with more adventure", eventually approaching Dana Olsen and Robert Collector. Richard Donner was attached to direct for eight months due to his experience with visual effects, something that made various potential directors turn down the project. Eventually someone suggested John Carpenter, and Chase approved the idea. Carpenter was then embroiled in a legal dispute with They Live production company Alive Films regarding his contract. He had several projects fall through: a film with Cher called Pincushion, Exorcist III, and a version of Dracula. He was reluctant to make Memoirs at first. "When you have lots of money and lots of time, it's really grueling. I enjoy being an independent, and it's not possible to be one in this situation. But then I thought. 'Why not?' I hadn't done a movie for a long time." The actor had to convince Warner Bros. that Carpenter, whom they still saw as a horror director, could work well for the picture.