The Mexican convent of St. Archangelo has a "bad rep" long before Sisters of Satan gets under way. The eponymous sisters don't seem to have a very firm grasp on the concept of giving one's life to one's Lord. When they finally determine that neither God nor the Virgin Mary can satisfy their spiritual needs, the nuns cast about for someone else to worship. That someone, as indicated by the title, is decked out with horns, a tail and cloven hooves. And just how did the lovely and graceful British leading lady Anne Heywood get herself mixed up in this monster rally? (Note how she never lists Sisters of Satan on her resume). ~ Hal Erickson, All Movie Guide