 | William Hurt als Professor Eddie Jessup |
 | Blair Brown als Emily Jessup |
 | Bob Balaban als Arthur Rosenberg |
 | Charles Haid als Mason Parrish |
 | Thaao Penghlis als Echeverria |
 | Miguel Godreau als Primal Man |
 | Dori Brenner als Sylvia Rosenberg |
 | Peter Brandon als Hobart |
 | Charles White-Eagle als The Brujo |
 | Drew Barrymore als Margaret Jessup |
 | Megan Jeffers als Grace Jessup |
 | Jack Murdock als Hector Orteco |
 | Francis X. McCarthy als Obispo |
| Deborah Baltzell als Schizophrenic Patient |
 | Evan Richards als Young Rosenberg |
| Paul Larsson als Charlie Thomas |
 | John Larroquette als X-Ray Technician |
 | George Gaynes als Dr. Wissenschaft |
 | Hap Lawrence als Endocrinology Fellow |
 | John Walter Davis als Medical Technician |
| John Corigliano | Original Music Composer |
| Ken Russell | Director |
| Jordan Cronenweth | Director of Photography |
| Howard Gottfried | Producer |
| Daniel Melnick | Executive Producer |
| Paddy Chayefsky | Novel |
| Eric Jenkins | Editor |
| Paddy Chayefsky | Screenplay |
| Thomas L. Roysden | Set Decoration |
| Howard Feuer | Casting |
| Jeremy Ritzer | Casting |
| Ruth Myers | Costume Design |
| Richard Macdonald | Production Design |
| Les Fresholtz | Sound Re-Recording Mixer |
| James Glennon | Camera Operator |
| Carline Davis-Dyer | Script Supervisor |
| Arthur Piantadosi | Sound Re-Recording Mixer |
| Gary Holt | Gaffer |
| Michael Colgan | Supervising Sound Editor |
| Michael Minkler | Sound Re-Recording Mixer |
| Paul Pav | Location Manager |
| Garrett Brown | Steadicam Operator |
| Morgan Renard | Still Photographer |
| John M. Woodward | Transportation Coordinator |
| Stuart Baird | Associate Producer |
| Michael Hancock | Makeup Artist |
| Rick Baker | Special Effects Makeup Artist |
| Dione Taylor | Hairstylist |
| Sidney H. Greenwood | Property Master |
| Tony Dyson | Props |
| Roger Irvin | Construction Coordinator |
| Sal Martorano | Electrician |
| Jeff Howard | Assistant Art Director |
| Carey Jones | Second Assistant Camera |
| Chris Strong | Electrician |
| Adam Glick | Lighting Technician |
| Gary Daigler | Assistant Director |
| Bob Rose | Key Grip |
| Johnny E. Jensen | First Assistant Camera |
| Rick Baker | Makeup Artist |
| Bran Ferren | Visual Effects Director |
| David Silver | Unit Production Manager |
| Peter Schindler | Second Assistant Director |
| Dick Smith | Special Effects Makeup Artist |
| Carl Fullerton | Special Effects Makeup Artist |
| Craig Reardon | Special Effects Makeup Artist |
| Joel Thurm | Additional Casting |
| Stephen Kolzak | Additional Casting |
| Christopher Keene | Conductor |
| Chuck Gaspar | Special Effects |
| Larry L. Fuentes | Special Effects Assistant |
| Donald Harris | Music Editor |
| Ronald C. Jacobs | Leadman |
| Stan Cockerell | Assistant Property Master |
| Willie D. Burton | Sound Mixer |
| Marvin E. Lewis | Boom Operator |
| Darryl M. Athons | Costumer |
| Shanan Harrell | Costumer |
| Thomas Penick | Assistant Editor |
| Arthur W. Forney | Assistant Editor |
| Lee Stitch | Production Secretary |
| Jay Wertz | Sound Editor |
| Fred Stafford | Sound Editor |
| Don Higgins | Sound Editor |
| Colin Waddy | Sound Editor |
| Laurey Condon | Assistant Sound Editor |
| Susan Tarr | Research Assistant |
| Scott Bartlett | Technical Advisor |
| John David Earnest | Orchestrator |
