Ingrid Pitt said in a 2009 column she wrote for Den of Geek that "When it came to the nude scenes, the director asked Madeline Smith and me if we wanted a closed set. It didn't bother me one way or the other because I've always been a bit of an exhibitionist so I had no problem letting people see me naked. Maddy Smith, being very British, was a little more nervous about prancing around in the nude. So we had a closed set. Producers Harry Fine and Michael Style were a bit peeved about this because they were barred from set too. They thought it was producer's perks to watch what was going on. Then one day I was walking to the set wearing just a dressing gown with nothing on underneath when I saw them coming in the opposite direction wearing a doleful look. As I went past them I open my dressing gown and said, Wheeeee! There was a spring in their step as they went on their way."
During an interview in 2000, Ingrid Pitt was asked if she was reluctant at all about her extensive nudity in this film. She replied: "I don't know about reluctant. I didn't think there was anything gross or indecent about what we were doing. I think Maddy Smith was probably a little more apprehensive than I was but I must salute [director Roy Ward Baker]. He gave us a closed set and treated it all as the most natural thing in the world. I do get people who seem embarassed when they buy nude photographs of me. They're very apologetic. I'm not sure why. It doesn't bother me. In fact I'm quite proud of the young bod. Something to show the grandchildren and remind them that Grandma wasn't always an old bag."
The director claimed that, after reading the novella Carmilla twice, he didn't get a sense of any lesbian content. Ingrid Pitt also claims she didn't play the role as though the vampire was a lesbian but asexual.
James Carreras rejected a suggestion that Bond girl Shirley Eaton play the lead on the grounds that she was too old. Ingrid Pitt, only 10 months younger than Eaton, was eventually cast.
While filming, Ingrid Pitt and the girls had a great deal of trouble getting through scenes without giggling. In the scene where Ingrid has to drink from Kate O'Mara, her vampire teeth kept falling out and into Kate's cleavage. She eventually had to steal some gum from one of the stagehands to stick the fangs back in.