The firehouse used as the Ghostbusters HQ was built in 1901 and used to serve as an actual firehouse in Athens, Georgia. It is now used as the headquarters of the Athens Heritage Foundation but still features the functioning brass fire pole.
At one point the Ghostbusters are listening to "I want a new drug" by Huey Lewis. Lewis once sued Ray Parker Jr. because he thought the "Ghostbusters Theme" too closely resembled this song.
The film was made using equipment and software belonging to the University of Georgia, who were unaware that most of the cast and crew had already graduated and were no longer eligible for checking out equipment or logging into the computers.
There were only three movie-accurate proton packs used in the film. A fourth pack was constructed from plywood and only shown from the front. When a shot was required to show all four Ghostbusters in gear from behind, something usually obscured the view of the fourth. The packs were also switched around from actor to actor to create the illusion that four "hero" packs existed.