| Name | Character | Episodes |
|---|---|---|
| Dennis Boutsikaris | Joe Calvo | 28 |
| Michael Learned | Mary Benjamin | 28 |
| Robert Reed | Dr. Adam Rose | 28 |
| Hattie Winston | Toni Gillette | 28 |
| Bonnie Hellman | Penny Brooks | 28 |
| David Morse | Kevin Mallory | 1 |
| Danny Aiello | Gene Halley | 1 |
| Robert Desiderio | Randy Sweet | 1 |
| Antonio Fargas | Marshall Gripps | 1 |
| Dwight Schultz | Dr. Kevin Michaels | 1 |
| Patrick O'Neal | 1 | |
| E.G. Marshall | Father | 1 |
| Anthony Zerbe | Sam Mancuso | 1 |
| Anthony Zerbe | 1 | |
| Shirley Knight | Sylvia Dennis | 1 |
| Paul McCrane | George Nicholas | 1 |
| Joe Silver | Agnello | 1 |
| John Rothman | Dr. Mitchell | 1 |
| Jacqueline Brookes | Dr. Patman | 1 |
| Caitlin Clarke | Kelly O'Neill | 1 |
| Philip Bosco | Dr. Harry Wallenberg | 1 |
| Steve Allen | Barney Ambler | 1 |
| Jenny Wright | 1 | |
| Frank Converse | Charles | 1 |
| Jill Eikenberry | 1 | |
| Leo Burmester | Wally | 1 |
| Margaret Hamilton | Mrs. Evers | 1 |
| Theresa Saldana | Rita | 1 |
| Julie Bovasso | Mrs. Mazzelli | 1 |
| Sam Freed | Fred Bremmer | 1 |
| Joshua Shelley | Ted Ambler | 1 |
| Cynthia Harris | Barbara Scholfield | 1 |
| John Cunningham | Frank Martin | 1 |
| Josh Clark | Steve | 1 |
| John Braden | Dr. Ransom | 1 |
| Peter Coffield | Dr. Benson | 1 |
| Joan Copeland | Beverly Thompson | 1 |
| Geraldine Fitzgerald | Helen McCall | 1 |