| Name | Character | Episodes |
|---|---|---|
| Dick Van Patten | Sgt. Nelson Higgenbottom | 20 |
| John Doucette | Capt. Aaron William Andrews | 20 |
| Don Adams | Det. Lennie Crooke | 20 |
| Rupert Crosse | Det. George Robinson | 20 |
| Robert Karvelas | 7 | |
| Yvonne Craig | 2 | |
| Ronald Long | 2 | |
| Cliff Osmond | 1 | |
| Bryan O'Byrne | 1 | |
| David Huddleston | 1 | |
| Ellen Corby | 1 | |
| Sid Haig | Charlie | 1 |
| Michael Fox | 1 | |
| John Abbott | 1 | |
| Jack Carter | 1 | |
| John Larch | 1 | |
| Liam Dunn | 1 | |
| Marc Lawrence | 1 | |
| Vincent Van Patten | 1 | |
| Jack Webb | 1 | |
| Bob Hastings | 1 | |
| Paul Picerni | 1 | |
| Hans Conried | 1 | |
| Norman Burton | 1 | |
| Richard Derr | 1 | |
| Rick Jason | 1 | |
| Laurel Goodwin | 1 | |
| Harry Townes | 1 | |
| Art Metrano | 1 | |
| JoAnna Cameron | 1 | |
| May Britt | 1 | |
| Mark Roberts | 1 | |
| Harry Bartell | 1 | |
| Bruce Gordon | 1 | |
| Foster Brooks | 1 | |
| Herbie Faye | 1 | |
| Paul Lambert | 1 | |
| Juanita Moore | 1 | |
| John Davis Chandler | 1 | |
| Marty Ingels | 1 | |
| Jack Somack | 1 | |
| Paul Comi | 1 | |
| Fred Holliday | 1 | |
| Len Lesser | 1 | |
| Jesse White | 1 | |
| Joey Forman | 1 | |
| Lee Delano | 1 |