Billing Displacement: Despite being third-billed and having co-starring billing Ben Johnson only has a handful of scenes.
The Cast Showoff: In addition to driving, Steve McQueen shows off his weapon handling skills that he acquired through his time in the Marines.
Cast the Expert: W. Dee Kutach, the Texas prison parole board chairman who denies Doc McCoy his parole in the opening minutes of the film, was actually a prison official at the time the movie was made - he was the Assistant Director for Treatment for the Texas Department of Corrections in Huntsville, TX.
Creator Backlash: Ali MacGraw said of the film, "I looked at what I had done in it, I hated my own performance. I liked the picture, but I despised my own work".
Enforced Method Acting: In the scene where Steve McQueen and Ali MacGraw are standing outside the car and McQueen suddenly slaps her, the slap was unscripted, as can be seen by MacGraw's shocked reaction.
The film was initially set in the 1940s, as the novel was.
Jim Thompson was originally hired to adapt his own novel for the movie. Thompson worked on the screenplay for four months and produced a prose treatment, a first draft, and alternate scenes and episodes. Thompson's script included the original borderline-surrealistic ending of the novel featuring the kingdom of El Rey. Steve McQueen objected to the depressing ending and had Thompson replaced with rising screenwriter Walter Hill.