Although filmed in spanish, the native language of most of the cast (Evelyn Stewart and Franco Fantasia shot in italian), the movie was completely dubbed and only main star, Analía Gadé, and Eduardo Fajardo kept their original voices, dubbing themselves.
Quite a success in Spain, the movie was blown up to 70mm for selected theaters.
One of 13 titles included in Avco-Embassy's "Nightmare Theater" package syndicated for television in 1975.
Mostly filmed in studio. The cemetery and the mansion setting itself was fully build inside Estudios Roma (Madrid). Only parts of the Mansion's facade were built. The movie uses models and in camera tricks for wide angle shots of it.
Italian censorship visa #60759 delivered on 7/28/72.