- James Whitmore as Dr. Spencer
- Tippi Hedren as Margaret Tenhausen
- Don Johnson as Stanley
- Laurie Walters as Sheila Grove
- Victoria Thompson as Alissa Carr
- Robert Fuller as Arthur Trent
- Bruno Kirby as Vernon
- Cindy Williams as Allison
- Keenan Wynn as Benjie
- Ray Milland as Dr. Charles Arlington
- Virginia Vincent as Maryanne
- Eric Braeden as Peter List
- Frank DeVol as Mr. Grove