Dick Powell starred in the Richard Diamond, Private Detective radio series as a wisecracking, former police officer turned private detective. Episodes typically open with a client visiting or calling cash-strapped Diamond's office and agreeing to his fee of $100 a day plus expenses, or Diamond taking on a case at the behest of his friend and former partner, Lt. Walter Levinson. Diamond often suffers a blow to the head in his sleuthing pursuits. Most episodes end with Diamond at the piano, singing a standard, popular song, or showtune from Powell's repertoire to his girlfriend, Helen Asher, in her penthouse at 975 Park Avenue.

Levinson was played variously by Ed Begley, Arthur Q. Bryan, Ted DeCorsia and Alan Reed. Helen was played by Virginia Gregg and others. Another regular cast member included Wilms Herbert as Walt's bumbling sergeant, Otis, who also "doubled" on the show as Helen's butler, Francis.

Many of the shows were either written or directed by Edwards. Its theme, "Leave It to Love", was whistled by Powell at the beginning of each episode.