Both the film's director William A. Levey and actor John Hart have stated that Joe De Sue was actually a one-time client of the film's producer Frank R. Saletri, a former criminal lawyer trying to break into show business.
It was originally planned to make an ongoing series out of this film. Depending on the source, there either would have been two sequels titled "The Fall of the House of Blackenstein" and "Blackenstein III" or one sequel titled "The Black Frankenstein Meets the White Werewolf", the latter of which was intended to be released in 1976. Whichever one of these situations would have been the case, all plans for a series were ultimately scrapped after the film failed at the box office.