For the role of Darkman, Sam Raimi wanted someone who could play a monster with the soul of a man, and could do all that beneath a lot of makeup. He also liked Liam Neeson's Gary Cooper charisma. Neeson was drawn to the operatic nature of the story and the inner turmoil of the character. To research the role, Neeson contacted the Phoenix Society, an organization that helps accident victims with severe disfigurements adjust to re-entering society.
Bill Paxton was almost cast as Peyton Westlake. According to Paxton, he told his friend Liam Neeson about the audition. When Neeson got the role, Paxton was so angry that he did not speak to Neeson for months.
Director Sam Raimi wanted Bruce Campbell to play the lead role, but the producers were uncertain that Campbell could handle the part. Campbell makes a small cameo in the very last scene instead.
Originated from a short story by Sam Raimi that paid homage to the Universal horror films of the 1930s.
Joel Coen and Ethan Coen, close friends of Sam Raimi, did some uncredited doctoring on the finished script.
Ethan Coen, Joel Coen: the director siblings and longtime friends of director Sam Raimi appear as Oldsmobile passenger and driver, respectively.