|Directed by||Ed Hunt|
|Produced by||Gerald T. Olson|
|Written by||Ed Hunt
|Music by||Arlon Ober|
|Cinematography||Stephen L. Posey|
|Release date(s)||April 28, 1981|
|Running time||85 min.|
June 9, 1970, three babies are born at the height of a total eclipse. Due to the sun and moon blocking Saturn, which controls emotions, the babies develop into children who are heartless and uncaring, with no feelings of remorse for their awful offences. In 1980, Curtis, Debbie and Steven begin to kill the adults around them and are able to escape detection because of their youthful and innocent façades. However when Timmy and Joyce discover their crimes,they find themselves as the targets of the evil children. Their attempt to warn their neighbors about them are ignored.
A young couple are fooling around in the cemetery at night and are killed by an unknown person. Later, Curtis, Debbie, and Steven are playing at Debbie's house where they set up an accident for Debbie's father, Sheriff Brody. Brody evades the set up but is beaten to death with a baseball bat. The kids set it up to look like he fell down the stairs and they get away with it. Curtis later takes Sheriff Brody's gun. Soon after, Curtis, Steven, another boy, and Timmy are playing hide and seek in the junkyard. While Steven counts, Curtis tells Timmy to get inside a refrigerator, and Curtis locks him in. Timmy manages to escape some time later. A couple days later, Curtis murders their teacher, Ms. Davis at school. Joyce stumbles upon the body and is brought home by a police officer. Around this time, Joyce and her younger brother Timmy start to grow suspicious of the three kids. At Curtis, Steven, and Debbie's birthday party, Curtis tricks Joyce into believing he poisoned the cake to make her look crazy. Soon after, Curtis murders a young couple in their van.
Soon enough, Debbie's sister, Beverly discovers Debbie's horrible secret with the newspaper clippings in the scrapbook as evidence and learns that she, Curtis and Steven were responsible for the murders, including their father. She realizes that Joyce and Timmy were telling the truth all along and confronts Debbie for it. Debbie blames the scrapbook on Curtis and Mrs. Brody forbids her from hanging out with Curtis. Debbie calls Curtis and tells him and Steven to come to her house. Despite being told to wait for them, Debbie responds by killing her older sister in retaliation with a bow and arrow.
The next day, Curtis, Steven, and Debbie attack Timmy and almost strangle him before Joyce finds them and stops them. Debbie once again blames Curtis and Steven and makes herself out to look innocent. The next day, Debbie asks Joyce and Timmy to babysit her later that night and Joyce agrees, not knowing it's a trap. When Joyce and Timmy get to Debbie's house, they are attacked by the kids. However, they fight back and manage to capture Steven and Curtis. While Timmy calls the police from a neighbor's house, Debbie manages to escape from the backyard and gets inside her mother's car. She lies to Mrs. Brody about Curtis and Steven, saying that they did something bad. Her mother believes her and escapes the scene with Debbie.
Afterwards, Curtis and Steven are charged by the police much to the shock and anger of the town. Before being taken away, Curtis gives an evil smile to Joyce and Timmy, intending for revenge. The last scene shows Debbie playing with a tool outside the motel room next to a truck and her mother comes out looking for her. It's revealed that they changed their names and moved to a different area. Her mother has Debbie recite her name again as Beth Simpson and she promises to be a good girl. After they leave, it's revealed that she has murdered a truck driver.
- Miss Viola Davis - Susan Strasberg
- Doctor - José Ferrer
- Joyce Russel - Lori Lethin
- Mrs. Brody - Melinda Cordell
- Beverly Brody - Julie Brown
- Mr. Harding - Joe Penny
- Sheriff James Brody – Bert Kramer
- Timmy Russel - K.C. Martel
- Debbie Brody - Elizabeth Hoy
- Curtis Taylor - Billy Jayne
- Steven Seton - Andy Freeman
- Duke Benson - Ben Marley
- Annie Smith - Erica Hope
- Madge - Ellen Geer
- Willard - Michael Dudikoff
- Paul - Cyril O'Reilly
- Girl in van - Sylvia Wright
- Guy in van - John Avery
- Classmate - Shane Butterworth
Bloody Birthday was given a belated limited release theatrically in the United States by Rearguard Productions in 1986. It was later released on VHS by Prism Entertainment in 1986 and Starmaker Entertainment in 1990.