 | George Segal als Harry Benson |
 | Joan Hackett als Dr. Janet Ross |
 | Richard Dysart als Dr. John Ellis |
 | Donald Moffat als Dr. Arthur McPherson |
 | Michael C. Gwynne als Dr. Robert Morris |
 | William Hansen als Dr. Ezra Manon |
 | Jill Clayburgh als Angela Black |
 | Norman Burton als Det. Capt. Anders |
 | James B. Sikking als Ralph Friedman |
 | Matt Clark als Gerhard |
 | Jim Antonio als Richards |
 | Steve Kanaly als Edmonds |
 | Al Checco als Farley |
 | Gene Borkan als Benson's Guard |
| Burke Byrnes als Benson's Guard |
 | Fred Sadoff als Police Doctor |
 | Robert Ito als Anesthetist |
 | Jason Wingreen als Instructor |
 | Jack Colvin als Detective |
 | Jordan Rhodes als First Questionnaire |
 | Ian Wolfe als Priest |
| Dee Carroll als Night Nurse |
 | Rutanya Alda als Nurse |
 | Lee de Broux als Reporter |
 | George Holmes als Reporter |
| Michael Jeffers als Reporter |
| Joe Pine als Reporter |
 | Bob Harks als Orderly |
 | Victor Argo als Orderly |
| Clark Ross als Orderly |
 | Michael Santiago als Orderly |
 | Nicholas Worth als Orderly |
| Mike Hodges | Director |
| Michael Crichton | Novel |
| Mike Hodges | Screenplay |
| Michael Dryhurst | Associate Producer |
| Mike Hodges | Producer |
| Robert L. Wolfe | Editor |
| Nessa Hyams | Casting |
| Fred Harpman | Art Direction |
| Marvin March | Set Decoration |
| Donald Brooks | Costume Design |
| Vittorio Nino Novarese | Costume Design |
| Leo Lotito Jr. | Makeup Artist |
| Fred Williams | Makeup Artist |
| Sherry Wilson | Hairstylist |
| Bruce Fowler Jr. | Production Manager |
| Margaret Tary | Script Supervisor |
| Richard H. Kline | Director of Photography |
| Robert Dijoux | Second Assistant Director |
| Dick Moder | First Assistant Director |
| Leonard S. Smith Jr. | Second Assistant Director |
| Harold Broner | Construction Coordinator |
| Herb Rindenow | Leadman |
| Willie Wiles | Assistant Property Master |
| Marty Wunderlich | Property Master |
| William Randall | Sound |
| Nicholas Stevenson | Sound Editor |
| Hugh Strain | Sound Mixer |
| Raul A. Bruce | Boom Operator |
| Charles Randall | Boom Operator |
| Douglas Pettibone | Special Effects |
| Loren Janes | Stunts |
| Albert Bettcher | Camera Operator |
| Kenneth Adams | Key Grip |
| Al Baerthlin | Assistant Camera |
| Wilbur Kinnett | Gaffer |
| Edward Morey III | Second Assistant Camera |
| Mel Traxel | Still Photographer |
| Ronald Vidor | First Assistant Camera |
| Jim Martell | Extras Casting |
| Charles E. James | Wardrobe Master |
| Tye Osward | Wardrobe Master |
| Edna Taylor | Wardrobe Master |
| Joel Cox | Assistant Editor |
| Jeremy Hume | Assistant Editor |
| R. Anthony Brown | Location Manager |
| Dan Wallin | Scoring Mixer |
| Ron Riner | Driver |
| Glenn Dunn | Craft Service |
| Kay Hoff | Production Secretary |
| William Koselka | Technical Advisor |
| Dorothy Naja | Production Secretary |
| Vernon White | Publicist |
| Glenn Gould | Musician |
