- Billing Displacement: Top-billed Jennifer O'Neill doesn't appear until the 37 minute mark and is more of a supporting character to Stephen Lack's character. Michael Ironside is billed fifth despite arguably playing the most memorable character of the film.
- The Danza:
Assistant to Mr Heroux.....Kim Obrist
- In Scanners 2 David Hewlett plays David Kellum.
- From the credits of Scanners
- Reality Subtext: A drug marketed to pregnant women as a painkiller that turns out to cause strange deformities in their unborn children; ephemerol bears an eerie similarity to the real-life scandal in the late 1950s as women who had taken thalidomide during pregnancy (marketed as relief for morning sickness) began to give birth to children suffering phocomelia or other physical deformities.
- Romance on the Set: Christian Duguay, the director of Scanners II and III, married Liliana Komorowska, who played Helen in the third.
- Technology Marches On: The very idea that someone could intrude upon a computer system via its connection to the phone lines seems to be an alien concept to Con Sec's security director. He and the Con Sec technicians ponder aloud exactly how it might work, presumably because audiences in 1981 would be equally confused by the notion.
- What Could Have Been: In the original screenplay, the protagonist's name was going to be Harley Quinn (note that Batman: The Animated Series did not exist yet) and he was going to be a much darker character than Vale - it was going to start with him Mind Raping a woman in a subway on purpose, as opposed to Vale's accidental crime in the opening scene of the completed film.
- Writing by the Seat of Your Pants: The first film was written like this, which was forced upon Cronenberg because of the way the production had to be structured due to financing reasons. There was virtually no pre-production, so he had to start shooting with an unfinished script. He would write in the morning, and film the rest of the day, mostly out of order. On top of that, they often had to drive around at random, looking for places to shoot scenes. So literally everything about Scanners was done by the seat of their pants. He talks about it at some length in Cronenberg on Cronenberg.