Most of the cutaway scenes (Otis torturing cheerleaders, Baby masturbating with the skeleton, etc.) were filmed in Rob Zombie's basement after filming wrapped. He would invite cast members over to his house on the weekends and shoot the footage himself with a 16mm hand-held camera. With the exception of the shot of a setting sun, he created the opening credits the same way.
In the DVDcommentary, Rob Zombie revealed that Jake McKinnon (The Professor) couldn't see very well in his costume. In the scene where he swings a real axe at Denise (Erin Daniels, his vision was so bad he could have seriously injured her if she didn't move fast enough. Rob says in his commentary, "We just assumed she would get out of the way."
The actual house is the same used in The Best Little Whorehouse in Texas (1982), which can be viewed during Universal Studios' tram ride. However, during filming Universal refused to stop the tram tours, which delayed filming during many scenes.
During its box-office run, the movie encountered two instances of the number 666: At the beginning of its run, when its opening weekend was $3,460,666, and at the end of its run, when its per-theater-average (the weekend gross divided by the number of theaters) was $666 per theater.
Rob Zombie considered appearing a few seconds into the film as Dr. Wolfenstein. However, after deciding that he would look "normal" no matter what make-up effects were used, he chose not to. Instead, he took on the brief role as Dr Wolfenstein's assistant (for about two seconds) and can be seen in the background and then smashing a pumpkin with a sledgehammer.
Rob Zombie has said that he was constantly shooting two versions of the gorier scenes to appease Universal. For instance, a shot at the start of the film in which the robber who was stabbed with the axe is on the floor was shot two ways: with blood and without blood. Several scenes were also shot twice involving regular lighting and red lighting to give it a more gruesome effect both of which were edited into the final cut. Note several scenes with cross-cutting involving sets lit with white light, and red light.
Near the beginning of the film, Capt. Spaulding tells Bill that he took over the shop "right after The Duke nabbed Oscar," speaking about John Wayne winning the award. Later in the film, Spaulding tells Wydell, "Don't get all true grit on my ass." This is a reference to his previous comment, as True Grit (1969) was the first (and only) time Wayne ever won an Oscar for Best Actor in a Leading Role.
Inside Capt. Spaulding's gas bar/fast food/museum of horror, behind the cash on the wall are reproductions of Aleister Crowley's paintings of demonic figures which were later discovered under whitewash in his former Abbey of Thelema, in Cefalu, Italy.
Final film of Dennis Fimple. NOTE: He was increasingly sick with heart disease during filming and for some of his last scenes He died in 2002, two years after this film was made but one year before it was released.
The film's script was constantly changing, leading to an entirely different ending at one point. Originally Grandpa Hugo was going to be revealed as the mad doctor (who in the rough cut was not even called Dr. Satan).
As Harrison Young's character looks out the window at the children trick or treating, you can see the house used in the original Munsters, located on the Universal back lot. His house is the home used in Leave it to Beaver.
In the burial scene towards the end of the movie where the caskets are lowered into the ground with a tape recorder, the recording is a slowed down clip of Aleister Crowley repeating "bury me in a nameless grave" which is the opening line from his poem "The Poet" recorded in 1920.
In 2014, Rob Zombie acknowledged the movie's cult following but admitted that he himself is not fond of it. Zombie called the film "a calamitous mess [...] All I see is flaw, upon flaw, upon flaw...upon flaw".
Capt. Spaulding (Sid Haig) says that he's been running his business since right after John Wayne won the Oscar, which he did in April 17 1970, for his performance in True Grit (1969). The date in the movie is supposed to be October 30, 1977, which means that Spaulding has been running the museum for about 7½ years.
Erin Daniels (Denise) was on The L Word (2004), which also starred Pam Grier. Grier and Sid Haig, who played Capt. Spaulding, made many films together during the "blaxploitation" era in the 1960s and 1970s.
In the "I Remember You" scene, Otis (Bill Moseley) uses a 1911 pistol to shoot at Don Willis (Harrison Young). The pistol used was a reference to Moseley's role in The Texas Chainsaw Massacre 2 (1986). in which he played a Vietnam veteran and Young's role in Saving Private Ryan (1998), in which he played a WW2 veteran. The 1911 pistol was the official sidearm of the US Army during the two wars.
In the "I Remember You" scene, Otis (Bill Moseley) uses a 1911 pistol to shoot at Don Willis (Harrison Young). It takes him from him holding the gun to his head, to him pulling the trigger, 26 seconds.