Actress Pamela Franklin and actor Harvey Jason (The Mad Hungarian from The Gumball Rally (1976)) met while making this picture - and have remained married to this very day. Franklin has said in interviews that her marriage is the only good thing to come out of this film.
Pamela Franklin didn't like working with Orson Welles because he was rude and "dismissive" of the other actors.
Orson Welles' biographer Josh Karp said Welles took part in the film merely for the pay.
The movie was given a theatrical release in 1972 from Cinerama Releasing. Then the original version was suppressed after its initial release in favor of a radically reworked version in the early '80s for the VHS market called The Witching, with the story severely reworked, extended scenes of fully nude coven worship added (including a young Brinke Stevens), and an entirely new, senseless ending replacing the original one. Star Pamela Franklin said in an interview that she was shocked by the new "soft core" version when she rewatched it.
Features the debut of Scream Queen fan-favorite Brinke Stevens as an uncredited fully nude extra during a new coven worship scene added to the re-edited "soft core" version released on VHS in the early 80s. She couldn't have performed that scene when the film was originally shot in 1970, because she would have only been 15 or 16.