Writer Donald E. Westlake stated in an interview that "The Hot Rock" started out to be one of his darker Parker novels but that "it kept turning funny."
Composer Quincy Jones was so impressed by the performance of his musicians for the soundtrack of the film that he asked 20th Century Fox and the producers of the film to give the musicians on-screen credit. The featured performers given credit on screen were (among others): Gerry Mulligan, Grady Tate, Jerome Richardson, Frank Rosolino, Clark Terry, and The Don Elliott Voices, who were all popular jazz musicians at the time.
During the helicopter scene, both towers of the World Trade Center can be seen under construction.
On its initial British release, the film's title was changed to "How To Steal A Diamond In Four Uneasy Lessons" on the grounds that people might think it was a rock-music concert film like "Woodstock". This title change was much disparaged at the time by journalists and members of the public. Later the film reverted to its slicker original American title for all of its TV screenings and home media releases in the UK.
In the Dortmunder novels by Donald E. Westlake, Kelp always steals cars owned by medical doctors. In the movie, viewers might notice that the license plates of the stolen cars have the letters "MD" as part of the plate number. Kelp believes that doctors have expensive tastes and thus their cars are usually loaded with the best options (leather seats, stereo, etc.).