Elaine May provides the voice of the Mayflower Hotel wake-up call operator.
Mia Farrow was slated to play Charlotte Randall. Mike Nichols had to fight to let Farrow have the part, due to the film company's hesitancy over her being too controversial at the time (the then current Mia Farrow/Woody Allen trial). She had to take a salary cut but in the long run she had to bow out anyway due to schedule conflicts.
The movie's release was delayed for 6 to 8 months to re-shoot the entire third act.
Although the film is about a werewolf, that particular word is never mentioned.
Jack Nicholson had been trying to get this film made with his friend, writer Jim Harrison, for 12 years.
In 'Christopher Plummer''s new memoir, he revealed that while filming a scene, he got so into character that he actually slapped Michelle Pfeiffer across the face instead of faking it.
In the scene where Will meets with Alden and his lawyer, in the bookshelves you can see six Robert Jordan books: One copy of 'The Eye of the World', one copy of 'The Great Hunt', two copies of 'The Dragon Reborn', and two copies of 'The Shadow Rising'.