Alternate versions

To capitalize on the success of The Exorcist (1973), some new footage, featuring Robert Alda as a priest, was shot. It involved Lisa (Elke Sommer) being possessed by a demon. The original cut of Lisa and the Devil (1973) was edited and used as flashback material to surround the possession theme. This resulting version was released in 1975 as "House of Exorcism."

The 90-minute Spanish version has an extended, gorier version of Sylva Koscina's death scene. However, the two sex scenes are severely re-edited and significant part of the ending is cut out.

The ending of "Lisa and the Devil" has Lisa boarding an airplane to go back home to America. She falls asleep and wakes up a little later, only to discover that the plane is deserted. She ventures to the front and discovers the bodies of the Countess, Max and others she encountered the previous night. Lisa runs to the cockpit and finds Leandro the Devil flying the plane. He pushes her back to the floor where she transforms into a mannequin of his lost love. The ending of "House of Exorcism" has Father Michael venturing to the abandoned mansion and trying to perform an exorcism on it in order to eradicate the demonic spirits within Lisa (who is still at the hospital). A flash of light, a fierce wind and an explosion indicate the house has been cleansed.