Kevin Costner was offered the role of Tommy Ray Glatman but turned it down because he did not want to play a supporting role.
Was the second film to be Rated PG-13 under then new MPAA ratings guidelines following Red Dawn (1984), which had come out weeks prior to this film's release.
Originally the producers wanted Maurice Jarre to write the music for the film orchestrally, but Jarre insisted on scoring the film electronically because he felt that it was the right approach for the material and also sets the tone of the film.
Dennis Quaid was the first and only choice for Alex Gardner, after the producers loved his dedication for the role and the project during its pre-production stage.
Kate Capshaw starred as the love-interest in not one, but two 1984 movies that featured a scene where a man's still-beating heart was ripped from his chest: this movie and Indiana Jones and the Temple of Doom (1984).
Originally there was a love scene involving Alex and Jane that was supposed to have taken place in the middle of the film involving nudity, but it was deleted for pacing issues and also because of the MPAA's new PG-13 rating guidelines. The love scene was featured in the film theatrically and on its original video release, but for its "Image" dvd release a PG edited cut print or TV version of the film was used for the transfer.
One of three movies to come out within a year of each dealing with dream manipulation and it's potential consequences. The other two were Brainstorm (1983), released a year earlier, and A Nightmare on Elm Street (1984), released 3 months later.
Christopher Plummer and Max von Sydow would be in competition with each other for the Best Supporting Actor Oscar in 2012, in which Plummer succeeded.
Christopher Plummer and Max von Sydow both voiced characters in the video game Skyrim (2011).
When George Wendt's character hands the book he wrote to Dennis Quaid's character, on the back is a quote plugging the book credited to David Loughery who wrote the story/screenplay for this movie.
Chuck Russell, who co-wrote the screenplay, was also the screenwriter for A Nightmare on Elm Street 3: Dream Warriors (1987), the third in the Nightmare On Elm Street franchise. Dreamscape and the Nightmare series share very similar plot elements, particularly the killer using the victim's dreams to kill them in reality.