 | Sandra Dee als Nancy Wagner |
 | Dean Stockwell als Wilbur Whateley |
 | Ed Begley als Dr. Henry Armitage |
 | Lloyd Bochner als Dr. Cory |
 | Sam Jaffe als Old Whateley |
 | Joanne Moore Jordan als Lavinia Whateley |
 | Donna Baccala als Elizabeth Hamilton |
 | Talia Shire als Nurse Cora |
 | Michael Fox als Dr. Raskin |
 | Jason Wingreen als Sheriff Harrison |
 | Barboura Morris als Mrs. Cole |
 | Beach Dickerson als Mr. Cole |
| Michael Haynes als Guard |
| Toby Russ als Librarian |
| Jack Pierce als Reeger |
 | Robert Nevin als Man in Cemetery (uncredited) |
| Curtis Hanson | Screenplay |
| Daniel Haller | Director |
| Henry Rosenbaum | Screenplay |
| Ronald Silkosky | Screenplay |
| Samuel Z. Arkoff | Producer |
| James H. Nicholson | Producer |
| Roger Corman | Executive Producer |
| Roger George | Special Effects |
| Raymond Boltz Jr. | Set Decoration |
| Paul Sylos | Art Direction |
| Christopher Holmes | Editor |
| Richard C. Glouner | Cinematography |
| H.P. Lovecraft | Novel |
| Jack Obringer | Makeup Artist |
| Jack Bohrer | Producer |
| Norman T. Herman | Production Executive |
| Jack Bohrer | Production Manager |
| Richard C. Glouner | Director of Photography |
| Sandy Dvore | Title Designer |
| Al Simms | Music Supervisor |
| Lew Borzage | Assistant Director |
| Richard Wimpy | Camera Operator |
| Gene A. Talvin | Assistant Camera |
| Jack Spicer | Gaffer |
| Charles Hannawalt | Key Grip |
| Richard King Sr. | Best Boy Grip |
| Charles T. Knight | Sound Mixer |
| Harry Harvey Jr. | Script Supervisor |
| Richard Bruno | Wardrobe Master |
| Faith Schmehr | Hairdresser |
| C. Randall Berkeley | Property Master |
| Tamara Asseyev | Production Assistant |
| Les Baxter | Original Music Composer |
