According to James Woods, his role in this film was one of his toughest because his character had to constantly be angry with Michael J. Fox's character, who he found very likeable in real life.
One of James Woods' perks was to have his own personal hairdresser, at a cost to the studio of $6,000 a week. The average on-set hairdresser usually costs about a third of that.
This was the last movie to feature the 75th Anniversary variant of the 1990 Universal Studios logo. Every other feature from Universal after this movie, up until McHale's Navy (1997), used a short variant.
In the movie theater where the Nick Lang movie is playing, and where the Party Crasher gets in the shoot-out with Michael J. Fox, there is a poster in the background for Bird on a Wire (1990), which was also directed by John Badham.
Fabio is briefly seen helping people out of the night club the first time the Party Crasher hits a club at the beginning of the movie.
The movie-within-the-movie "Smoking Gunn II" features music very similar to Alan Silvestri's score for the "Back to the Future" films, which also starred Michael J. Fox.
The film was originally slated to shoot for sixteen weeks, but it was reduced to thirteen because producer and second unit director Rob Cohen was shooting at the same time as John Badham in different locations, to save more time and money.
Director of photography Robert Primes was fired halfway through filming by director John Badham and replaced with Donald McAlpine. Badham thought Primes was working too slowly. He had similar complaints during the filming of Bird on a Wire (1990), their previous, and first, movie together.
During one of the attacks on Nick and John, one of the bankers is stand-up comic Lewis Black.
Penny Marshall (Angie) and Kathy Najimy (Lang's Girl Friday) also worked together on Hocus Pocus; Najimy as witch Mary Sanderson and Marshall as the wife of her real life brother, Gary Marshall.
During the club scene where The Party Crasher makes his first on-screen kill, the song "Momma Said Knock You Out" is playing in the background. This was LL Cool J's hit single at the time, and he also featured as one of James Woods' NYPD partners in the film.
At one point Michael J. Fox's character yells "I'm driving here, I'm driving here." In Back To The Future part two, Marty McFly's son (Also played by Fox) utters a similar line: "I'm walking here, I'm walking here."
Despite the fact that Moss is struggling to quit smoking he is never seen lightning a cigarette, only smoking one in the scene when he's on a stakeout with Pooley.