Just so Danielle Harris wouldn't be scared, George P. Wilbur would often lift up his mask between takes to remind her that they were just making a movie and that he was not really going to hurt her.
The girl Lindsey who drove Rachel and Jamie to the discount mart was going to be revealed as Lindsey Wallace from Halloween - La notte delle streghe (1978) and have a larger part in the film as Rachel's friend and helping her babysit Jamie, but that was cut for budget reasons. The third boy hanging out with Brady and Wade in the drug store was meant to be Tommy Doyle from the original film.
Danielle Harris revealed in 25 Years of Terror, when her character runs through the neighborhood screaming for help someone legitimately called the cops, "I was banging on doors, yelling for someone to help me, help me, after I got lost trick or treating or something. So, 4 o'clock in the morning, they're hearing a little screaming up the streets, and someone called the cops. The cops came. Then the story ended up in The Inquirer that I was almost kidnapped off of the set."
Dwight H. Little did extensive research on the history of Halloween and many of its harvest images were put in the creepy opening sequence.