Trivia

In the background at the new facility, the Slime Blowers used in Ghostbusters II (1989) can be seen. One of the engineers is spraying another, perhaps to test the effects of the slime.

Bill Murray has frequently been cited as a reason any kind of sequel to Ghostbusters II (1989) took so long to make. The actor's reputation as a "loose cannon" and his desire to distance himself from the franchise for many years led many fans to believe that movies such as Ghostbusters: Afterlife (2021) and this film would never be made. However, director Gil Kenan, who directed Murray in City of Ember (2008), suggests that getting Murray back for this movie was quite easy, revealing: "Well, you know very well that Bill and I have a history because we made a movie together in 2007, a movie that almost cost [Bill his] life. That was the Hall H experience, and we won't go into too much. But it opened the door for Bill and I to have a relationship that has remained dynamic over the years. We've stayed friends, we've kept in touch. When I reached out to him to say that we were creating a story for Peter Venkman in this film, he was really enthusiastic."

When Gary says he picked out a film for movie night, he holds up a VHS copy of Cannibal Girls (1973). This was the second feature film directed by Ivan Reitman who directed Ghostbusters (1984) and Ghostbusters II (1989). He's also listed as a producer on this film which is dedicated to him. The title "Cannibal Girls" can also be seen on a movie theater marquee in both Ghostbusters II (1989) and Ghostbusters: Afterlife (2021).

The film is dedicated to Ivan Reitman, the director of Ghostbusters (1984) and Ghostbusters II (1989), who passed away on February 12, 2022.

According to Mckenna Grace, it was somewhat more difficult (at least for her) to work with the surviving original cast compared to Ghostbusters: Afterlife (2021) where the original actors came in late in the film and were only on set for 2 weeks to shoot the climax. In this installment, the original cast were on set for about 90% of the shoot. Grace admitted that while it was fun working with them and hearing their stories, she also felt a little intimidated and worried about screwing up in front of the guys who started this whole thing 40 years ago.