One scene involved using over 3,000 snakes including pythons, boas, water snakes, garter snakes, rat snakes, and a 10-foot Amazon constrictor - even rare albino snakes.
Robin Tunney wore an orange-blond wig throughout filming because she had shaved her head for her role in Empire Records which wrapped up filming only a month before production on this movie began.
The shots of Nancy being covered in bugs were created by wrapping a life-cast of Fairuza Balk's head and torso in green screen material. The bugs were filmed crawling all over the casting and then digitally composited on top of a live action plate of Balk.
On the special edition DVD of this film, Andrew Fleming states in the commentary that the production was geared toward earning a PG-13 rating from the MPAA. They followed all of the guidelines to earn that rating, but in the final outcome the film was rated R because the film dealt with teenage girls using witchcraft.
Although the name of the Catholic high school is never mentioned in the film, it was referred to as St. Bernard's Academy in the film's trailer. This is a nod by writer Peter Filardi to the real Saint Bernard High School in southeastern Connecticut, where Filardi grew up.
After Sarah returns to her house near the end, the house is full of snakes, rats, maggots, etc. As she retreats to the upstairs bathroom, we see her pass a whiteboard with the name Gustav Klimt. Gustav Klimt was an artist whose works were denounced for their eroticism. He was also known to have a common theme of the "Femme Fatale" or women who were empowered and strong.
In the shooting script, as well as early edits of the film, it is implied that only Sarah has actual magic powers, and that the other girls' abilities are merely a result of their leaching off of Sarah's magic.
About the invocation scene, Sony Pictures' World Wide Web site at the time the film was featured on its website has to say: "The crew had to return to the location a second time to complete filming interrupted by several weird occurrences that even caused witch consultant Pat Devin to raise an eyebrow. As the fog rolled in at midnight, the four actresses used actual Wiccan rites and language to invoke powerful forces. Then, as Fairuza Balk's character Nancy attempts to invoke the deity Manon, a flock of bats hovered over the set and the tide rose dramatically, extinguishing the circle of candles. Witchcraft consultant Devin recalls that 'Manon, a fictitious creation for the film, sounds very close to Mananan, the Gaelic god of the sea. Luckily, we weren't all swept to sea!'" The Web site quotes director Andrew Fleming: "'Every time the girls started the ceremony, and only when they would start the ceremony, the waves would start coming up tremendously fast, pounding heavily. Then, right when Nancy says her line, "Manon, fill me," right at that exact moment, we lost power. It was a very strange thing.'"
While researching The Craft, Fairuza Balk became familiar with Panpipes Magickal Marketplace in Hollywood, eventually buying the store and continuing to operate it until 2001 when she sold it to Jymie Darling and Vicky Adams, whom she had brought in as managers after her own purchase in 1995.
Actress Fairuza Balk is actually a Wiccan in real life. Balk was also able to help the makers of the movie keep the storyline as realistic as they could, and was able to give them Wicca contacts to help them in areas she couldn't.
One of the first films to use Kodak's EXR 200T 5287 film stock. Cinematographer Alexander Gruszynski had been planning to use it sparingly, but liked it so much during tests that he decided to shoot most of the film with it.