| Name | Character | Episodes |
|---|---|---|
| Timothy Hutton | Archie Goodwin | 27 |
| Maury Chaykin | Nero Wolfe | 27 |
| Bill Smitrovich | Inspector Cramer | 27 |
| Colin Fox | Fritz Brenner | 18 |
| Fulvio Cecere | Fred Durkin | 5 |
| Conrad Dunn | Saul Panzer | 5 |
| R.D. Reid | Sergeant Purley Stebbins | 4 |
| Trent McMullen | Orrie Cather | 4 |
| Saul Rubinek | Lon Cohen | 3 |
| Carrie Fisher | Ellen Tenzer | 2 |
| Cynthia Watros | Phoebe Gunther | 2 |
| James Tolkan | FBI Agent Richard Wragg | 2 |
| James Tolkan | Leo Bingham | 2 |
| Joe Flaherty | Dr. Vollmer | 2 |
| Julian Richings | Alger Kates | 2 |
| Julian Richings | Poet | 2 |
| George Plimpton | Winterhoff | 2 |
| Peter Mensah | Receptionist | 1 |
| Kari Matchett | Celia Grantham | 1 |
| James Tolkan | Richard Wragg | 1 |
| James Tolkan | Mr. Hackett | 1 |
| Julian Richings | Jerome Aland | 1 |
| Julian Richings | Peter Jay | 1 |
| Francie Swift | Sarah Dacos | 1 |
| Nicky Guadagni | Ivana Althaus | 1 |
| Nicky Guadagni | Elaine Usher | 1 |
| Boyd Banks | Austin 'Dinky' Byne | 1 |
| Seymour Cassel | Dazy Perrit | 1 |
| Seymour Cassel | James Arthur Ferris | 1 |
| George Plimpton | Cook | 1 |
| Marian Seldes | Louise Grantham Robilotti | 1 |
| Debra Monk | Rachel Bruner | 1 |
| Sarain Boylan | Nora Jaret | 1 |
| Ken Kramer | Dr. Vollmer | 1 |
| R.D. Reid | Purley Stebbins | 1 |
| Gretchen Egolf | Marian Hinckley | 1 |
| Marty Moreau | The Driver | 1 |
| Michael Rhoades | Beverly Kent | 1 |
| Aron Tager | Bernard Fromm | 1 |
| Aron Tager | Commissioner Fromm | 1 |
| Kathryn Zenna | Helen Yarmis | 1 |
| Robert Bockstael | Timothy Quayle | 1 |
| Robert Bockstael | Paul Schuster | 1 |