Around one hundred digital effects shots appear in the film, mostly to create gore. The scenes involving objects coming into direct contact with skin (like throat slitting, people getting shot in the head or neck, or stabbings) were created digitally. The violence that didn't involve direct skin contact (like people getting shot in areas covered by clothing) were achieved practically. Rob Zombie originally intended to create all of the special effects using only techniques available in the 1970s, but time constraints prevented this.
The film originally had a subplot involving scenes with Dr. Satan. In an interview, Rob Zombie said that he cut these scenes because seeing Dr. Satan in this film would be like seeing Chewbacca in Bonnie and Clyde (1967). Zombie then went on to explain that all the Dr. Satan scenes would be restored in the "deleted scenes" section of the the DVD.
Rosario Dawson originally had a small part as a nurse in the film. Her character was cut out of the theatrical release for Rob Zombie's decision of not having any Dr. Satan in the film. Her character was killed off within forty seconds of her debut to the film.
The Family Media Guide claims the word "fuck" and its variations are used 224 times in this film, however other sources list the count at 560 which, until the release of Fuck (2005) was a record (the previous holder was Nil by Mouth (1997) which had a count of 470).
Sheri Moon Zombie's brother has a cameo as a police officer in the opening shootout scene. He was originally only on the set as a visitor, but director Rob Zombie put him in the scene because he knew how to handle firearms well.
The name Charlie Altamont was inspired by The Rolling Stones documentary Gimme Shelter (1970) - where a Hell's Angels member brutally stabbed a youth to death at Altamont Speedway in Northern California. In the film, Charlie Altamont "gives shelter" to the Firefly family.
The anchorman is named Derek Sanderson after the NHL player of the same name who played for the Boston Bruins during the '70s. Director Rob Zombie has mentioned during multiple interviews his affinity for the Bruins as a child growing up in Massachusetts.
The shoot out at the beginning of the film is very reminiscent of Australian bush-ranger Ned Kelly and his gang's last stand at Glenrowan. The armor, and the scene's presentation, are very similar to other film representations of Ned Kelly's tragic final defense.
Matthew McGrory (Tiny Firefly) hurt his ankle before shooting. The crew had to find a stunt double to replace him during his scenes where his face was covered with the burlap sack. When the actor takes off the sack, it is Matthew McGrory.