Dylan Thomas' screenplay was written in the 1940s, but plans to film it fell through. His screenplay was published shortly after his death in 1953. The script attracted the attention of Director Nicholas Ray in the mid 1960s, although it was elaborately re-written to transfer the action from Scotland to Vienna. Ray announced that he would make the film in Belgrade, with Maximilian Schell and Susannah York, but the production was abandoned before shooting began. The project was inactive for another twenty years.
At thirty-two years, this holds the world record for the longest delay between the completion of the script, and the making of the movie.
Dr. Thomas Rock is based on Dr. Robert Knox. Rock is played in this movie by Timothy Dalton. In real-life, Dr. Knox's association with the Burke and Hare murders damaged his reputation and ruined his career.
Director Freddie Francis was appalled to learn that Producer Mel Brooks originally intended to use none of Dylan Thomas' original screenplay, but wanted simply another horror movie about Burke and Hare. Francis insisted on going back to the Thomas script as far as possible, although certain revisions were made by Ronald Harwood.
The Burke and Hare murders, on which this movie was based, were based on fact, and were a true story. The Burke and Hare (William Burke and William Hare) characters in this movie, are known instead as Robert Fallon and Timothy Broom. The legendary Burke and Hare murders are also known as the West Port murders. The total number of deaths amounted to seventeen.