Producer 'Douglas, Michael' considered several directors, including Mark Rydell, Adrian Lyne, John Badham and 'Scott, Tony' , before settling on John Carpenter.
Jeff Bridges' character (Starman) walks in and buys a Cadillac "cash". In the 1974 film Thunderbolt and Lightfoot, Bridges character (Lightfoot) exclaims that one day he would like to walk up and buy a Cadillac with cash.
This script was being developed at Columbia at the same time as another script about an alien visitation. The studio did not want to make both, so the head of the studio had to choose which film to make; he decided to make this one and let the other script go to a rival studio. The other script was for _E.T. the Extra-Terrestrial (1982)_ .
The role of Starman originally went to Kevin Bacon.
When Jeff Bridges walks outside the house naked and uses a 'marble' his hair seems to stand on end. This effect was actually created by shooting Bridges hanging upside-down and then matting the shot onto the background the right way up to give him a surreal look.