Will and Hank Deutschendorf, the twins who play Oscar, are the nephews of singer John Denver.

In the scene when Egon looks up information about Vigo in the database, Vigo's full name is listed as Vigo Von Homburg Deutschendorf. The actor who plays Vigo is Wilhelm von Homburg and the twins who play Oscar are Will and Henry J. Deutschendorf II.

Several pieces of material from the trailers did not appear in the film: - Egon uses a PKE meter to read a piece of floating crystal. - When someone says the Titanic just arrived, Venkman replies "Better late than never." In the film, this is said by Cheech Marin.

Dialogue including "There's always room for Jello" was re-recorded for the finished film.

Cameo: [Chloe Webb] guest on "World of the Psychic".

The kid who tells Ray that, according to his dad, the Ghostbusters are "full of crap" is played by Jason Reitman, the son of director Ivan Reitman. Reitman's daughter plays the girl with the puppy in Egon's lab.

Originally, the producers planned on having the crashed Hindenburg appear as a ghostly blimp. They dumped this in favor of the apparitions coming off the Titanic.

At the beginning of the second ghost montage, a movie theater is shown that is playing the movie Cannibal Girls. Cannibal Girls (1973) was director Ivan Reitman's second movie.

The scene involving a woman's mink coat coming to life was originally written & storyboarded to be in the first film.

When Peter arrives at Ray's Occult book-store, pretending to be a strange customer looking for a particular book, the gag was originally intended to be that Peter had previously made a prank phone call to Ray asking for the book, and Ray realizing it was Peter who made the call when he arrives at the store repeating the act. The prank call was not used in the final edit of the film, resulting in it seeming that Peter is just fooling around as he enters the shop.

A scene of Egon and Ray experimenting on the bowl of slime, with them wearing head devices with multiple wires connecting to the bowl (which would have gone before the scene with the 'dancing toaster'), was filmed but not used in the final edit, but a shot from the scene was a commonly used publicity still for the film.

The shot of the Ecto-1 on the verge of breaking down at the start of the film is fitting in that while filming the bridge scene that's seen in the montage, the car finally did break down.

A scene featuring Ray driving Ecto-1 recklessly at speed, as a result of being possessed while conducting tests on Vigo's painting, was filmed but not used in the final edit of the movie. However, some shots of the sequence (Ray running a red light; Peter, sitting in the back, pulling a surprised face) were used in the montage as the Ghostbusters go back into business. (This continued a trend of unused scenes being used in montage - in the first film, a scene of Ray and Winston investigating a haunted castle, where Ray encounters a beautiful ghost, was filmed and not used, but instead used as a 'dream' in that movie's montage sequence.)

200 visual effects shots were used in the entire film.

In the German dub of the movie Dana's child Oscar is renamed to 'Donald'.

The original VHS issue of this movie (and Karate Kid III) were in Letterbox, causing complaints to video stores prompting them to call RCA/Columbia to find out if there was a problem in the printing.

The joystick the team uses is an NES Advantage joystick with most of the body removed.

The phone number on the side of Ecto-1 is JL5-2020. (555-2020)

The cameo appearance of Slimer the green ghost of the first film was prompted by the fact that in the years in between the two films, the cartoon series "The Real Ghostbusters" introduced the idea that Slimer was living at the firehouse as the Ghostbusters' pet. Because the original film and the cartoon series were so popular with children, they put Slimer in the film.

During the montage sequence after the courthouse scene, when the Ghostbusters sign is being put up, the sign-maker's phone number, (516) 374-2340, is visible. This was and still is the phone number for Five Town Neon Service Inc., also known as "Johnny's Signs".

In the courtroom scene, the prosecuting lawyer is carried out of the room upside-down by her leg by one of the ghosts. In the trailer, you see the prosecuting lawyer floating out of the room upside-down as the ghost SFX have not yet been added.

The pneumatic subway line that Ray finds when they lower him below the street actually exists under part of Manhattan. The line was built prior to any other subways in the area and was actually built without any City approval. It operated using compressed air and pushed Victorian New Yorkers a number of blocks in "elegant comfort". When the City of New York found out about the subway line, they shut it down and the line was buried, including two beautifully appointed stations with extensive tile work and even full-size chandeliers above the tracks! Several decades later, when digging for the modern subway system, workers punched into the then unknown subway tunnel and found the station and the subway car completely intact and in remarkably good condition. It's still there today.

Bill Murray told Entertainment Weekly he was very disappointed with the way the film turned out. He commented "it was a whole lot of slime, and not much of us."

This film is the final theatrical appearance for actress Janet Margolin, (prosecution lawyer) who died three years later from ovarian cancer.

In Peter's apartment you can see the newspaper front pages from the first Ghost Busters (1984) movie, including the "USA Today" front page. Each one is framed on his wall. They are most visible when Dana (Sigourney Weaver) is still wrapped in a towel after getting out of the shower and Peter is telling her about finding slime residue in her apartment.

Continuity

In the close-up of Ecto 1A's license plate near the end of the film, the Statue of Liberty is in the middle of the plate. In all other shots, it's on the left side of the plate.

Peter and Dana are waiting for a taxi outside Peter's apartment building when the Ectomobile pulls up. The license plate on the front says ECTO-2. The revamped Ectomobile was intended to be called ECTO-2 but was later changed to ECTO-1A. The scene must have been shot before the change was made.

The carriage with Oscar stops on First Avenue, and shops are in the background. Ten minutes later, when the Ghostbusters are digging in the street, a parking lot is in the background.

When Ray, Egon, and Winston enter the room with the heads on poles, Winston's helmet disappears and reappears between shots.

When Ray and Egon examine Oscar, the tape recorder jumps between Ray's left and right hands between shots.



Factual errors

(at around 1h 14 mins) When Janine, Louis, and Dana are in Peter's apartment watching a movie, a window opens in the room with the baby in it. Dana feels the breeze on the back of her hair and goes to investigate/check on the baby. Considering the door to the baby's room was closed and none of the other windows in the apartment appear to be open, there is no way she could have felt that breeze.

The camera Peter (Bill Murray) uses to take pictures of the painting (a Brooks Veriwide) would not be appropriate for this kind of photo shoot even though the description of the camera says (when used properly) : "It's great: it's very sharp at every aperture, there is no distortion and there are no ghosts.''



Incorrectly regarded as goofs

(at around 15 mins) During Oscar's examination, Egon suggests they perform an "Apgar score" test on baby Oscar. However, Apgar score is a test made on newborns only (usually 1 and 5 minutes after birth), so such a test would be entirely irrelevant in Oscar's case. This is a gag to show that the guys don't know what they're talking about.

Early in the film, Frank tells Dana "I'm not the doorman, Miss Barrett. I'm the building superintendent." At the end, Michael P. Moran is credited as playing "Frank the Doorman." It's a joke, to acknowledge what he said at the beginning.

In the statue, Peter stands next to Winston, who stands next to Ray, who stands next to Egon. It the next shot, Winston is next to Peter, who is next to Ray, who is next to Egon. In the following shot, they're back to their first configuration. Considering the space and the amount of time passed, it's entirely possible that they deliberately changed places.

(at around 1h 26 mins) When asked if she (Lady Liberty) can go faster, Ray denies it because the vibrations could damage her. Presumably, she got off the pedestal on Liberty Island very slowly and carefully, using all four limbs.

When the Ghostbusters drop in to the museum, Ray and Winston both have lights on their "slime throwers". These lights switch from on and off between shots until the end. The proton packs have activator switches on the wands, to conserve power, so the slime throwers could have the same.



Revealing mistakes

When Egon, Winston, and Ray enter the cavern of slime, they kick down a wall of rocks. While looking around, Ray sits down on one and it squishes.

When Ray and Egon run the photo of Vigo through the spectronalyzer, the analyzed version of the photo is completed when the original photo is halfway in the machine.

The movie takes place in New York in December, yet the city has very little snow and few Christmas decorations.

When Venkman steps on the pedal to trap the "jogger ghost" activate the ghost trap, his foot misses the button, but the trap opens anyway. The trap is actually opened by the pedal switch next to that "button".

The power cord to the computer on Janine Melnitz's desk is not plugged into the computer.



Anachronisms

The "City of Albany" ghost train, which is said to have derailed and wrecked in 1920, consists of a late 19-century locomotive and cars. Railroads still used that equipment in 1920, but a "name train" would have used modern, up-to-date equipment.



Audio/visual unsynchronized

In the courtroom, when one of the ghosts flies through the wall behind Ray, Egon yells "behind you, Ray!", but his mouth says something else.

When Dana gets to Peter's house after the bathtub scene, Oscar is crying. In closeups, the baby is not crying.

When Raymond and Egon arrive at Peter's rendezvous with Dana, they tell Peter about their plans to go underground. Ray clearly speaks to Peter, but only Egon's mouth moves.

When Dana is talking to Frank at the beginning, she says "You're also a human being, Frank." Whilst she can be seen mouthing the word 'Frank', she cannot be heard saying 'Frank'.



Crew or equipment visible

Near the end, when Vigo moves the boxes and other items to reveal where Oscar is hiding, part of someone's arm pops out from behind the pillar at the left side of the screen.

When the jar of pink slime starts to boil In the courtroom scene, the mechanism and pump making it move are visible.

The camera crew is reflected in the dancing toaster.

Small pegs jut out the bottom of the dancing toaster.

(at around 1h 16 mins) During the "Flip City" song montage, when the large monster ghost is coming through the arch, the green screen to the right, at the top of the arch, is still visible.



Errors in geography

When the mayor is looking out the window from his office, the eclipse appears to be over Central Park as seen from Central Park West. City Hall is downtown, too far to see Central Park.

When the Ghostbusters are being brought to City Hall, the police car has red and blue emergency lights. New York City police cars have red and white emergency lights.

When the Con Edison Supervisor and the police arrive at the hole on First Avenue, a subway station exit nearly has red lights on top. The only one subway station on First Avenue is the L train, and all of the exits to that station have green lights on top.



Plot holes

People still don't believe the Ghostbusters found slime underground at the trial many days later. In order for the real electricians to get the city lights working again, they would've had to go underground to do all the repairs in the location where Ray caused the damage, and they would've discovered the river of slime for themselves.

It is established that no one believes in the Ghostbusters or the paranormal. However, in the first movie the citizens of New York were terrorized by ghosts, the Staypufft Marshmallow Man, and supernatural forces in the sky above the skyscraper when Gozer came to Earth. Reporters even filmed the events. Five years later, no one believes anymore.

When the Ghostbusters arrive at the museum in The Statue Of Liberty, they descend from the crown on ropes. The windows on the crown are not large enough for them to fit through on their own, much less with their equipment.

Hardemeyer has the Ghostbusters committed to Parkview Psychiatric Hospital for observation, claiming to be acting on the mayor's behalf. A mayor's office does not have the authority to commit an individual. Also, three of the four Ghostbusters are doctors of psychology, making it highly unlikely that the hospital would admit them without question or suspicion.



Character error

Ray, Egon, and Winston go down into the sewer to examine the slime. Winston is using a measuring device to see how deep it is when he is pulled towards the slime. Egon and Ray try to hold him back, and one of them calls Winston "Ernie."

When Louis is being outfitted with a Ghostbusters jumpsuit, the name tag says "Spengler" and it is the correct size, even though Egon is about a foot taller than Louis.

In the case against the Ghostbusters breaking their restraining order, the court never bothered to have Dana testify. She asked them to help her and Oscar, making her an accessory to them digging the 1st Avenue hole.

When Peter is trying to hail a cab, he's standing on a one-way street, yet he's facing the opposite way of the direction of traffic.

When Louis is watching Citizen Kane (1941), he says Rita Hayworth was married to Orson Welles when it was filmed. They married two years after the film came out.