Silva plays the title character, but we first get to know him as a rebellious Sicilian child. He becomes a cult hero in Sicily, but is eventually arrested by the authorities and sent to Rome. There he makes a deal with a fugitive US mafia boss called Johnny Colini. Against his will, he is tricked into playing Colini's son and sent to the States. His mission is part strategy, part revenge and the end game is to bring the Colini family back to the top. Rounding out the cast is an all-star cast of '60s actors, including Telly Salavas, Jim Backus, Mort Sahl and a couple of real Rat Packers.
Produced in part by Peter Lawford, this B-movie mafia thriller is very coolly filmed and contains no social commentary on violence. Silva is excellent and the intriguing cast delivers some great performances throughout. The strong screenplay by Joseph Landon is based on the novel "The Kingdom of Johnny Cool" by John McPartland. The remarkable neo-noir style jazz score was composed, arranged and conducted by Billy May, and Sammy Davis Jr. also sings the title song "The Ballad of Johnny Cool".