According to co-producer Dennis Stuart Murphy, the idea to have Jason wear a burlap sack over his head in Part 2 came from their costume designer, who figured it was the type of readily available item Jason could have conceivably and easily procured.
Following the release of Vendredi 13 (1980), Adrienne King had numerous encounters with an obsessive fan which escalated into a stalker case, and she chose to retire from acting after this film. She later returned to the profession in 2010 with the film Psychic Experiment (2010).
The first Jason scene in the movie is a shot of Jason's legs walking across the street toward Alice's house. This is the only time in the series Jason was played by a woman: Ellen Lutter, the film's costume designer.
Warrington Gillette's agent told him he had a part for a Camp Counselor for him (Paul), and he auditioned, but didn't get the part. The producers liked him, and knew he had gone to stunt school, so they asked him to be Jason.
In the scene when Jason crashes into the window and grabs Ginny, the actor, Warrington Gillette was actually hurt. He tried to break into the window, only it didn't break, and he ended up banging his head really hard on the glass.