When passing through solid objects, ghosts appear to absorb some of the material they are going through. Jerry Zucker had some difficulty explaining what he wanted this effect to look like. Finally, he illustrated it by dipping a napkin into coffee.

Vincent Schiavelli played the subway ghost in the scenes with Patrick Swayze's character. Both men subsequently died of cancer at the age of 57.

The film's iconic love scene, where Sam helps Molly on a potter's wheel and begins kissing her as "Unchained Melody" by The Righteous Brothers plays, has been parodied in several formats, most notably The Naked Gun 2½: The Smell of Fear (1991), as Ghost director Jerry Zucker was heavily involved in the making of all three Naked Gun films, having written part of the first film and being executive producer of the other two. The scene in question involved Leslie Nielsen and Priscilla Presley.

When Patrick Swayze hosted "Saturday Night Live" (1975), he reprises his role as Sam Wheat in a sketch parodying the movie in which he tries to communicate with Molly, played by Victoria Jackson; but is put off by her disgusting habits (since she thinks she is alone). When "Oda Mae" (Chris Rock) arrives, he tells her "(she's) a pig. I'm hauling my ass up to Heaven."

Molly tells Sam that he "leads a charmed life." This is a line from Macbeth. Macbeth also claims to lead a charmed life - meaning he cannot be killed. Immediately after making this claim, however, he is killed. Sam is killed after seeing a production of Macbeth.

The subway scenes were filmed on the abandoned lower level of the 42nd St. station of the IND 8th Ave. line. Trains appearing in the film wrong railed through the station; that is, they ran in the opposite direction of normal operation.

Shortly before production began, Whoopi Goldberg was not sure that she was going to be able to put this movie into her work schedule. The part was then verbally offered to Jackée Harry who accepted. However, at the last minute Goldberg was able to do the film and Harry was dropped.

Cameo: (Charlotte Zucker) Director Jerry Zucker's mother (who has appeared in many of the Zucker brothers' movies) plays the bank officer.

Producers originally offered the role of Sam to Bruce Willis, Demi's husband at the time. But he turned it down, because he didn't think the film would work.

Meg Ryan turned down the part of Molly.

The scene where Whoopi Goldberg meets two nuns is very prophetic. A couple of years after Ghost, Goldberg played a nun in Sister Act (1992). One year later, she repeated the role in Sister Act 2: Back in the Habit (1993).

When it came time to cast the film, writer Bruce Joel Rubin suggested Patrick Swayze for the role of Sam Wheat. Director Jerry Zucker felt that Swayze was completely wrong for the part. Many actors that included Tom Hanks, Tom Cruise, Kevin Bacon, Al Pacino, Bruce Willis, Harrison Ford, Nicolas Cage, Mickey Rourke, David Duchovny, Johnny Depp, Chevy Chase and Alec Baldwin were all offered the part but all turned it down feeling that playing a ghost would be cheesy. Zucker then decided to audition Swayze though he thought he would blow the audition. To Zucker's surprise, Swayze did a great audition and he was cast immediately in the part.

When Sam follows Willie to his apartment, he learns that his surname is 'Lopez' from the name tag on the apartment call button. Sam passes this info on to Oda Mae. However, the name 'Lopez' is a 'Dynotape sticker' obscuring the real name of the occupier. This probably explains why 'Willie Lopez' has no police record when Molly passes this info on to the Police detective.

Nicole Kidman originally auditioned for the role of Molly.

When the movie was first released on VHS in 1991, the tapes were light or "ghost" grey.