Jake and the Fatman

• William Conrad as District Attorney J. L. "Fatman" McCabe
• Joe Penny as Detective Jake Styles
• Alan Campbell as Assistant District Attorney Derek Mitchell

• Lu Leonard as Gertrude
• Jack Hogan as Judge Smithwood
• Melody Anderson as Sergeant Neely Capshaw

Guest stars on the series included Alex Cord, Robert Culp, Denise Dowse, Scott Marlowe, Leigh McCloskey, Ed Nelson, Leo Penn, Stephen Quadros, Robert Reed, Mitch Ryan, Alan Scarfe, David Soul and Ray Sharkey.

Conrad guest starred as an aging prosecutor in a two-part episode of Matlock during its first season on NBC. Executive producers Fred Silverman and Dean Hargrove decided to use this character as a model for one of the main characters in a new show they were creating for CBS. Penny also guest starred in these episodes, but his character was not on the same side as Conrad's character in the storyline's legal case.

Following the departure of Hargrove, executive producers David Moessinger and Jeri Taylor were brought on to run the series with Silverman. They also hired J. Michael Straczynski as an executive story consultant.[6] Taylor and Moessinger ran the show for two years before finally leaving in a dispute over control over the show.[6]

Straczynski has written that he was hired after pitching a story that let Conrad sit down for almost every scene,[6] noting his own faux slogan for the show "Jake and the Fatman: He can't act, he can't walk, together they fight crime".[6]

Joe Penny lost a large amount of weight after the show moved to Hawaii, which led to many rumors about his health, including the possibility that he had AIDS. In actuality, he had suffered from a gastrointestinal virus and was having difficulty regaining the weight he lost. When the show moved back to Los Angeles, it was also suspected that it was on Penny's urging. This was also not true, as the move was CBS's decision.[7]