Remember the geek that had milk come out of his nose when Heather #1 looked right at him? Well the the producer said that the geek gave a very "De-niro-like" performance because he put gelatin capsules of milk in each nostril, and they had to wait to shoot the scene until the capsules had melted a little and were ready to burst.
Friends Veronica Sawyer and Betty Finn are named after other fictional friends Veronica and Betty from the comic strip "Archie", and Tom Sawyer and Huckleberry Finn.
Heathers was also known as: Fatal Game, Lethal Attraction & Westerberg High.
The high school is named Westerberg High; Winona Ryder's favourite band at the time was The Replacements, whose lead singer is named Paul Westerberg.
J.D. tricks Veronica into killing the jocks by claiming to use "ich luge" bullets which he claims only pierce the skin. Ich luge is German for I'm lying.
The police officers are named Milner and McCord, after Kent McCord and Martin Milner, who played police officers in Adam 12.
Right before the students at the pep rally "hear" the explosion, the flash of light that cues them to turn around can be seen.
In the scene where J.D. and Veronica are preparing a poison to kill Heather, the poison bottle is seen from far away with its cap off, then has the cap on when filmed close up.
When they come out of the bathroom, Heather Chandler has the red clipboard. When Veronica walks towards JD she has it. Also, when she is asking JD the lunchtime poll, the position of the clipboard changes. An editing error.
A police officer drops his baton, but has it back while chasing JD and Veronica.
When Martha Dumptruck is alone in the gym drinking her soda through a straw, we see through the bottom that she finishes it all. She then spills the finished soda on the front of her shirt.
Veronica and Heather's positions change as they separate at the end of the film. The camera is over Veronica's shoulder as she is on the right of the screen. When it changes to Heather Duke, Veronica is still on the right when she should be on the left.
Sounds Pictures Facts Characters Quotes Body Count Multimedia Links Soundtrack Versions Laserdisc Merchandise Credits Scripts Sequel In the opening scene where the Heathers are playing croquet, Heather McNamara is wearing a wig.