The inspiration for the design of the telepods came from the shape of the cylinder in director David Cronenberg's vintage Ducati motorcycle. Brundlefly's "vomit drop" was, in reality, made from honey, eggs, and milk.
The scene where Seth and Ronnie are having coffee at the restaurant and is talking endlessly was only half scripted, while the remainder was written the night before the scene was going to be filmed, as Jeff Goldblum felt that he could add more to the character.
Scripted, but never filmed, was a segment meant to have followed the deleted monkey-cat scene: A homeless lady screams after interrupting Brundlefly as he feeds out of an open dumpster. Brundlefly seizes the bag lady and disintegrates her face with his vomit drop. Before he finishes feeding on the woman's corpse, Brundlefly's humanity emerges for a moment; just long enough to contemplate the horror of his sub-human existence.
Seth's saying, "Drink deep, or taste not, the plasma spring", is a reference to a famous quote from Alexander Pope's "An Essay on Criticism". The full quote is: "A little learning is a dang'rous thing; drink deep, or taste not the Pierian Spring: Their shallow draughts intoxicate the brain, and drinking largely sobers us again."
An Opera based on this movie is currently being produced for the stage in 2008. David Cronenberg is directing, Howard Shore has composed the music and the lyrics have been written by David Henry Hwang.
Chris Walas had a meeting with his crew prior to production. He said they could do this film or Gremlins 2: The New Batch. Working on this film meant that they would have to come up with all of the designs and begin construction in three months. Walas' crew unanimously agreed that it wasn't possible in that time frame but decided to do anyway because it was more of a challenge.
The first name mentioned in the end credits is Chris Walas, Inc. as the creator and designer of the fly. After a screening the audience cheered upon seeing this first credit. Producer Stuart Cornfeld turned to Walas and said, "You're getting the Oscar". Cornfeld's prediction came true when Walas did in fact win the Academy Award for Best Makeup. Walas claims that this was probably because his name was listed first.
The infamous cat-monkey scene where Brundlefly fuses a cat and the remaining baboon and then beats it to death with a lead pipe was cut following a Toronto screening. According to producer Stuart Cornfeld the audience felt that there was no turning back for Seth and they no longer empathized with his plight which caused the rest of the film to not play as well. In Cornfeld's own words: "If you beat an animal to death, even a monkey-cat, your audience is not gonna be interested in your problems anymore".
The first bar and the last bar of music on the soundtrack is taken from the last bar of music from Puccini's tragic opera 'Madama Butterfly'. Perhaps a reference to the deleted dream sequence of the heroine giving birth to a butterfly.
Michael Keaton was offered the role of Seth Brundle, but he declined.
There's a line in the film referencing Franz Kakfa's Metamophosis, a story about a man waking up transformed in a giant insect
David Cronenberg makes an Appearance in the film as a doctor, this due to the fact that earlier he met Martin Scorcese and he told him he looked like a Hollywood plastic Surgeon
Tim Burton was originally set to Direct this film
This film was the original source of the famous line "Be afraid, be very afraid"
Some of the later stages of makeup would take nearly five hours to apply on Jeff Goldblum.