Mark Damon played both Karl and Franz Schiller, but the cast list credits Sergio Pislar as Karl. Pislar was Mark Damon's double.
In his book Vampire Films of the 1970s, Gary A. Smith described the film as "a throwback to gothic horror" and that it appeared to be influenced by Hammer vampire films of the 1970s, specifically Twins of Evil.
Italian censorship visa #62028 delivered on 14-3-1973.