Producer Peter Locke has a memorable cameo as Mercury, the imbecile-sounding gang member with the feathered head-dress who is only spotted twice throughout the film, firstly at Fred's garage and secondly communicating with Mars and Pluto using a USAF radio.
The dead dog used as a stand-in for the family's slaughtered Alsatian 'Beauty', widely believed to be a dummy dog, was in fact a real (already dead) dog that director Wes Craven and producer Peter Locke had bought from the county sheriff's department.
When originally submitted to the MPAA, the film was given an X-rating which would have relegated it to the porno circuit and severely hurt the box-office returns. Wes Craven cut the film enough to secure an R rating, and the original director's cut is thought to be no longer in existence.
The desert locations for the film were extremely rough on the crew. Not only was the rocky terrain difficult to walk, let alone run through, but the temperature would reach up to 120 degrees during the day. After sunset though it would drop to a cold 30 degrees in a matter of minutes.
In an interview with star Suze Lanier-Bramlett she said that her agent strongly opposed her taking a role in the film fearing that it could ruin her career opportunities. However Lanier, who was a fan of the horror genre, liked Wes Craven so much that she went ahead and took the role of Brenda Carter anyway.
Auditioning for the role of Ruby required the actresses to have a foot race. When Wes Craven shouted for the actresses to go, Janus Blythe stood behind for a moment. Then after a moment took off and beat all the other actresses to the finish line. She was given the role.
According to Suze Lanier-Bramlett the tension was at first quite high when the crew prepared to shoot the scene where Pluto rapes Brenda. As a gag to break the ice for everyone Lanier and Michael Berryman started making out during the first take. The whole crew laughed hysterically.
The rattlesnake used in the film actually escaped while preparing to shoot a scene in a narrow mountain crevasse. The entire crew fled at once from the narrow passage frightened. Minutes later the snake wrangler went in and recaptured the snake.
Wes Craven's original title for the film was 'Blood Relations'. Producer Peter Locke however disliked the title. Numerous titles were then considered and the film tested best under the title 'The Hills Have Eyes', though Craven himself initially disliked the title.
Virginia Vincent's reaction to being shot was quite genuine as there was a mishap with the squib planted under her robe. The small explosion caused her a deal of pain and she was briefly taken to the hospital.
Janus Blythe at first refused to pick up the rattlesnake in the film. Producer Peter Locke tried to convince her to pick it up, but Blythe said she would only do it if Locke would pick it up too. Peter Locke quickly touched the snake and Blythe complied by picking up the snake in the scene.
Star Michael Berryman said he was once watching the film in a theater when a woman in front of him said aloud 'this movie is sick and depraved!' Berryman then thought it would be funny to lean over her and say 'you're damn right lady this movie is sick!'
Michael Berryman's condition (Hypohidrotic Ectodermal Dysplasia) means he has a lack of sweat glands, among other things. Despite this, he worked on the movie for five months in 100+ degrees heat out in the desert.
The trivia items below may give away important plot points.
The movie is based on the legend of Sawney Beane and his family (a wife, eight sons and six daughters), a feral clan who inhabited and roamed the highlands of Scotland's East Lothian County, near Edinburgh, in the early 1400s. They captured, tormented and ate several transients. They were eventually captured on the order of Scotland's King James, were judged to be insane, and executed without trial. The executions of the Beane clan all allegedly involved grotesque tortures, inspiring the aspect of the film that the Carter family become as brutal as their attackers when they seek revenge.
Originally the ending of the movie wasn't as abrupt as it is on screen. There was additional footage shot after Doug kills Mars where we seeing the surviving Carters coming back together with Doug and Ruby. They embrace and Brenda takes Ruby by the hand and they walk away. The footage however was never used in the film in favor of a conclusion that was more shocking and bleak.