Martin Sheen agreed to star in this movie because he always wanted to star in a comic book movie. He later played another comic book role, Uncle Ben in The Amazing Spider-Man (2012).
John Leguizamo ate live waxworms on pizza for this film. He then vomited immediately after the take was wrapped.
Michael Jai White found Al Simmons' character appealing; he described Spawn as "the most tragic character I've encountered in any cinematic production." He says it was a challenge to make audiences sympathize with a government assassin who comes back from hell. White had to endure two to four hours of make-up work, including a full glued-on bodysuit, yellow contact lenses that irritated his eyes, and a mask that restricted his breathing. He said that his long-time experience with martial arts helped him endure the uncomfortable prosthetics, giving him "strong will and unbreakable concentration."
In one scene, Clown says "I'm not the Vindicator or the Victimizer or the Vaporizer or the Vibrator! I'm...The Violator!".
In the Spawn comics there are five Phlebiac Brothers, which are denizens of Hell called Violator, Vandalizer, Vaporizer, Vindicator and Vacillator.
Todd McFarlane: When Spawn is fighting the Violator, he encounters a frightened homeless man. This is the creator of the Spawn comic book.