Ghostbusters III is a proposed project. During his interview with Mike McGuire on CISN Country 103.9 FM in Edmonton, Alberta, Dan Aykroyd announced that Ghostbusters III: Hellbent will be CGI. "I can do all the things I wanted to do for much, much less money," he stated. Aykroyd wrote the script, which was described by IGN as being "too technical", with a new team of Ghostbusters that were not clearly delineated and had no group conflict or leading personalities.[19] Bill Murray has been thought to have held up the making of a third Ghostbusters movie, despite Aykroyd's enthusiasm, due to his preference that the movie be animated and his dislike of sequels.[20] However, he has now signed on to make the movie now that it will be CGI.[21] Harold Ramis is already attached. Sigourney Weaver has not expressed enthusiasm at doing another sequel.
Harold Ramis mentioned in 2005 that he wanted Ben Stiller to take Bill Murray's part in the then titled Ghostbusters in Hell.
The plot was to follow the three Ghostbusters attempting to find a replacement for Bill Murray's character while dealing with ghosts rejected from hell.
Aykroyd later elaborated, now that Murray is on board, that in the movie "We go to the hell side of Manhattan, downtown, Foley Square. It's all where the cops are--they are all blue minotaurs. Central Park is this huge peat mine with green demons there, surrounded by black onyx thousand-foot high apartment buildings with classic red devils, very wealthy. We go and visit a Donald Trump-like character who is Mr. Sifler. Luke Sifler. Lu-cifer. So we meet the devil in it".
Jason Reitman, the son of Ghostbusters director Ivan Reitman, has stated that he has little interest in directing the movie.
He was a guest on The Howard Stern Show on April 10, 2008; when he was asked if he would direct Ghostbusters 3 and cast Howard, he said "do you know how many times I get asked if I want to do Ghostbusters 3? Looking at my career so far, I mean if you just looked at my two films, I would make the most boring Ghostbusters movie. It would just be people talking about ghosts, there wouldn't be any ghost-busting in it." Ernie Hudson told Moviehole.net, that Ghostbusters III is still very much a possibility. He said he hoped that the new video game would generate renewed interest in a 3rd Ghostbusters film.
On September 4, 2008, Columbia Pictures signed on Lee Eisenberg and Gene Stupnitsky (writers for the U.S. version of The Office) to script a third film. No deals will be made with the original cast until the script is complete.[29] The story will feature old and new Ghostbusters.[30] Ramis had collaborated with Eisenberg and Stupnitsky on The Year One. Judd Apatow is also producing that film, and has made other films for Columbia, so they hope he will provide cast members for Ghostbusters III. Dan Aykroyd, Harold Ramis and Ivan Reitman are consulting on the project, and Bill Murray will be involved on some level.