Robert Patten, who plays Barnaby's son, Hal, was only 17 years younger than Buddy Ebsen. Lee Merriwether, playing Barnaby's daughter-in-law, Betty, was 27 years younger.
Frank Cannon's apartment does not resemble either of the apartments Cannon had in his own show. He had a huge luxury apartment in the Cannon pilot and a smaller one in the regular series episodes but it's different than the one shown here.
Barnaby drives a 1972 Ford Ranchero.
Bradford Dillman appears in the Barnaby Jones series six times and twice on Cannon.