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.
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.
This movie came about when Warner Brothers greenlit and financed Clint Eastwood's pet project Bird (1988), a biopic of musician Charles "Yardbird" Parker, Jr. Eastwood, returning the favor to the studio, agreed to make a movie for them that would be commercial and carry box-office weight. Warner Brothers suggested another Dirty Harry movie. Although Bird (1988) was filmed first, its release was delayed until the awards season in late 1988, with The Dead Pool being released during the summer of that year.
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.