Tom Savini once said in an interview that the corpses in the film were made using human skull plastic model kits which were glued to bodies made of chicken wire and painted cotton. The corpses' faces were created by taking plaster casts of various relatives of the crew members, including producer Tom Karr's wife.
Before the release of the film Ed Gein (2000), this film was the most accurate media portrayal of the story of Ed Gein at the time.
Harvey Keitel and Christopher Walken both auditioned for the role of Ezra Cobb in New York. Tom Karr felt they were a bit too young for the part, though. Roberts Blossom was the last to audition and Karr knew he had his man.
Director Bob Clark, who had previously directed the horror films Children Shouldn't Play with Dead Things (1972) and Dead of Night (1974) with Alan Ormsby and Jeff Gillen, was originally approached to direct this film, too. However, Clark felt its script was too disturbing for his taste, so he opted to co-produce it instead, though he was uncredited.
Micki Moore signed a contract to do a nude scene in the film. When it came time to do the gruesome scenes with Ezra, she flat out refused to do full nudity and stayed in her bra and panties instead.