Comic book creator Rob Liefeld admitted that the title of this movie was the inspiration for the name of his Marvel Comics anti-hero character Deadpool.
In the outdoor elevator action sequence, Patricia Clarkson stated how she was petrified when the elevator was shot at by a blaze of deafening and frightening firepower, but was comforted greatly by Clint Eastwood who, as Dirty Harry, covered and protected her. Clarkson has revealed that the bullets from the battery of Uzis were in fact marbles.
The car chase sequence was inspired by the one in the earlier Steve McQueen movie Bullitt (1968). There was an intention to top that car chase with this movie. Reportedly, the sequence is Clint Eastwood's favorite from the movie.
According to the documentary on the Special Edition DVD set, the movie critic who gets killed is based upon famed critic Pauline Kael. It was Kael who, when critiquing Dirty Harry (1971), accused Don Siegel and Clint Eastwood of making a "fascist" and "racist" movie. The critic in this movie is made up to resemble Kael as she appeared during this movie's release as an in-joke.
Guns N' Roses: Uncredited, the members of rock group Guns N' Roses, W. Axl Rose, Slash, Izzy Stradlin, Duff McKagan and Steven Adler, appear in the movie in the funeral and pirate tug sequences. Their hit song "Welcome to the Jungle" was used in this movie, and was featured in trailers.
Harry Demopoulos: Clint Eastwood's real-life doctor, billed as Harry Demopoulos M.D., as a medic in the hospital room.
Durk Pearson: Uncredited, Clint Eastwood's friend and one of the movie's story writers as a man in the pirate tug nightmare scene.