[1] The film is about a team of scientists who follow a trail of corpses in New York to a remote Indonesian island where they meet a mad doctor (Donald O'Brien) who performs experiments on both the living and dead in his laboratory.

Dr. Peter Chandler investigates, and he and Lori discover that similar corpse mutilations have occurred in other city hospitals, where immigrants from this region are working.

The crew is hunted by cannibals and zombies, the latter created by the sinister Doctor Obrero, who is experimenting with corpses.

[2] It was released in the United States in 1982 in modified form, under the title Doctor Butcher M.D..[2] The Doctor Butcher cut features the film uncensored and uncut, but features a new prologue which consists of footage from an unreleased film shot by director Roy Frumkes, intercut with footage of the zombies from the film and footage of a swinging sign outside a building that said "Doctor Butcher M.D.".

[3] In 2016, Severin Films issued a deluxe edition two-disc Blu-ray that included both Zombie Holocaust and Doctor Butcher M.D., as well as a multitude of bonus features.

The first 5,000 copies of this edition also included a replica of the "barf bag" given out at some original screenings of Doctor Butcher M.D.