Loosely based on real-life killer/cannibal Ed Gein, whose story also inspired, among other films, Blutgericht in Texas (1974) and Psycho (1960).
According to director William Girdler, the truck Billy drives in the film wasn't working on the night when the scene where Billy picks up the four girls was shot, so crew members had to push the truck into the shot to make it appear that it 'drove' up. This is also the reason why we don't hear the motor running during this scene.
Filmed in and around Louisville, Kentucky, home of director William Girdler.
Much of the cast also appeared in William Girdler's debut film Asylum of Satan, which was released the same year as Three On A Meathook. Stars Charles Kissinger, James Picket, and Sherry Steiner appeared in both Girdler films.
William Girdler wrote and performed portions of the music score, including the piano and recorder tune heard during the closing credits.