This was the feature film debut for director Fraser C. Heston, who had played the infant Moses in The Ten Commandments (1956). During the filming, he took Max von Sydow (who played Jesus in The Greatest Story Ever Told (1965)) aside to discuss how he would play the upcoming scene. One observer noted, "That's something you don't see every day - Moses telling Jesus how to play the devil."
The setting of Needful Things is a fictional town called Castle Rock, Maine - as in Stephen King's novel. The distribution company Castle Rock was named after it when it released Stand by Me (1986). Castle Rock was also the setting for The Dead Zone (1983), Cujo (1983), and The Dark Half (1993). It was also the setting for Stand by Me
Brian Rusk's mother appears in the longer, 3 hours version. In her sidestory she purchases sun glasses worn by Elvis Presley. She can still be seen in the cut version of the movie at the end wearing the sun glasses.
In the film, Hugh Priest buys Gaunt a football jacket while, in the novel, he buys a fox's tail just like the one he used to fix to the car's aerial. If you look closely, the tail is visible during the flashback scene, just when Hugh tries the jacket in the store.
Fraser C. Heston, at the behest of the TNT cable network, prepared a two-part miniseries edit of the film which included over an hour's worth of material cut from the theatrical version. This version was advertised under the title "More Needful Things." Despite Heston's involvement, he does not consider this version a Director's Cut. Due to legal issues, this version has not been released on video.
Bonnie Bedelia previously appeared in "Salem's Lot (1979)(TV)', which was also based on a 'Stephen King' novel, and was also about a mysterious stranger who moves into a small town and opens an antique shop. That film also featured two actors (James Mason and Clarissa Kaye-Mason) who were a real-life husband and wife, as does this film (Ray McKinnon and Lisa Blount). They also both featured an actor whose spouse appeared in another film featuring the same characters. Julie Cobb appeared in Salem's Lot, which her husband James Cromwell appeared in the remake in 2004. Ed Harris's character previously appeared in The Dark Half (1993), which featured his wife, Amy Madigan.