This is the only Classic Who appearance of the Sisterhood of Karn, who would not be seen again until The Night of the Doctor (2013).
Christopher Barry said in an interview with Doctor Who Magazine that he considered Peter Cushing and Vincent Price for the role of Solon.
This story was a rewrite by script editor Robert Holmes of a script originally by Terrance Dicks. Although the final version retained the Frankenstein influence in Dicks' original, Holmes made fundamental changes to the story and the dialogue was entirely his, which resulted in Dicks asking for his name to be taken off. Holmes followed Dicks' advice to invent a "bland pseudonym" as writer of the story, which is why the name Robin Bland was credited.
The version by Terrance Dicks was about a space criminal called Morbius (likely named after the character in Forbidden Planet (1956)) who crashlands onto a planet, and his robot servant - who lacks any sense of aesthetics - assembles a new body for him from other aliens, in ignorance of their vastly differing physiognomies. Dicks drew partly upon the costumes for the Clawrantulars, creatures which had appeared in the stage play Doctor Who:Seven Keys To Doomsday, for the crab-like elements of Morbius' new body. He also decided to set the action upon the planet Karn (which had been the home of a decayed civilisation in the stage play) and took inspiration from H. Rider Haggard's 1886 serial novel "She" in developing the Sisterhood of Karn and their Flame of Life.
Mary Whitehouse said this serial "contained some of the sickest and most horrific material seen on children's television".