The film's storyline concerns an American psychologist (Andrews) who travels to England to investigate a satanic cult suspected in more than one death.

To accelerate the pace and make the film more commercial, the 96-minute original feature was trimmed down to 82 minutes prior to its release in the United States.

[3] This shortened version was retitled Curse of the Demon, playing in June 1958 as the second half of a double feature with either The True Story of Lynn Stuart (1958) or The Revenge of Frankenstein (1958), depending on the local film market.

[4] Though not a significant commercial success on its initial release in 1957, Night of the Demon has been highly acclaimed by critics and filmmakers in retrospect, and is considered one of the greatest horror films of all time.

Dr. John Holden arrives in Britain to attend a convention at which Harrington had intended to expose Karswell's cult.

He is informed that the only link between Harrington's death and Karswell's cult is a man suspected of murder, Rand Hobart, who has fallen into a catatonic stupor.

A powerful wind comes through the window, blowing the parchment from his fingers towards the fireplace, only to be stopped by a fire screen.

A medium claims to channel Harrington, who tells them that Karswell has the key to reading the runes in his copy of the rare book.

After Holden abruptly exits, dismissing the séance as nonsense, Joanna says she intends to search for the key and they drive to Karswell's mansion.

Against Karswell's warning, Holden leaves through the woods, and believes he is chased by a cloud of smoke and fire before escaping.

Screenwriter Charles Bennett owned the rights to the original story "Casting the Runes" and wrote a screenplay loosely based on it, using the title The Haunted.

[12] Producer Chester and his British co-producer, Frank Bevis, had decided to show the demon at the beginning and end of the film.

Stop motion master Ray Harryhausen was requested by Columbia Pictures to create the demon for the production, but he was already committed to his Dynamation film The 7th Voyage of Sinbad with producer Charles H. Schneer.

In the United States Curse of the Demon toured drive-ins and theatres as a double feature with either The True Story of Lynn Stuart or The Revenge of Frankenstein.

[15] In the United States, the film was released on VHS in 1986 by Columbia TriStar Home Video with a run time of 83 minutes.

[18] In a contemporary review, The Monthly Film Bulletin wrote: "This essay in the occult is handled with much of the assurance the same director brought to Cat People (1942), and is well above average.

Inevitably the sequences where the demon takes on a visible form are the weakest – especially in the ending – and seem rather the product of a child's nightmare than an adult's imagination.

[8] Kate Bush used a clip from the film featuring the line, 'it's in the trees, it's coming', in her hit single, "Hounds of Love".