According to director George A. Romero, in the commentary track he did for The Crazies (1973) in 2002, this is the only one of his films he'd like to remake. He cited lack of money as a reason for unhappiness with this production as it turned out.
Editing for this film is legendary. Rumor has it that, when Romero was finished with the final edit, nearly half of the film lay on the cutting room floor.
According to the making-of featurette "Digging Up the Dead: The 'Lost' Films of George A. Romero," when Joan Mitchell, Jan White, said the line "I'm a witch" during filming, the overhead ceiling cracked. Romero attributed this to heat from the lights, but said that some people on set were a little spooked by it.
When Halloween III: Season of the Witch (1982) was released this film played Times Square in NYC as George Romero's Season of the Witch.
The film's original title was Jack's Wife, which could be seen on VHS copies of the film.