This was to have been the first in a series of films. The poor box office cancelled those plans. The poor returns also contributed to the decline in the box office track record of Hammer Films.
Horst Janson's German accent was deemed too thick to be properly understood, so Julian Holloway was brought in to loop his entire performance.
Caroline Munro, who refused to do nude scenes throughout her career even though she was constantly offered roles that required it, was asked once about her "nude" scene in this film and she said: "I didn't want to do it. We discussed it beforehand, because I didn't feel it was really necessary. But they wanted it to appear nude, so we came to a compromise. My hair was a lot longer in those days. The locks covered my upper chest, so I actually used some sort of gaffer's tape to stick it down, so I felt quite secure in that sense. And then I donned a pair of flesh-color knickers and I was all right, it was like being on the beach, really." When asked about her attitude about nude scenes in general, she replied "Oh, I suppose that was the way films were going in general. I sort of came in at the end of it. I always feel my time would have been more in the '50s, when it was more in the imagination than like now. These days, you can see everything-sadly, nothing is left to the imagination."
After Dracula A.D. 1972 (1972), this was the second and final film that Caroline Munro made under her Hammer contract.
Although no further movies of Kronos were made, his adventures were continued in two comic books published 40 years apart. "The House of Hammer #1-3" (October 1976-January 1977) and "Captain Kronos - Vampire Hunter #1-4" (Titan Comics 2017).