| Robert Stack | Eliot Ness |
| Neville Brand | Al Capone |
| Bruce Gordon | Frank Nitti |
| Walter Winchell | Narrator |
| John Beradino | Johnny Giannini |
| Pat Crowley | Betty Anderson |
| Abel Fernandez | William Youngfellow |
| Barbara Nichols | Brandy La France |
| Paul Picerni | Tony Liguri |
| Keenan Wynn | Joe Fuselli |
| Wolfe Barzell | Picco |
| Richard Benedict | Furs Sammons |
| Wally Cassell | Phil D'Andrea |
| Frank de Kova | Jimmy Napoli |
| Paul Dubov | Jack Rossman |
| Eddie Firestone | Eric Hansen |
| Bern Hoffman | Jake Guzik |
| Peter Leeds | Lamarr Kane |
| Peter Mamakos | Bomber Belcastro |
| Joe Mantell | George Ritchie |
| Robert Osterloh | Tom Kopka |
| James Westerfield | Ed Marriatt |
| Frank Wilcox | Beecher Asbury |
| Bill Williams | Martin Flaherty |
| Anthony George | Actor |
| Nick Giorgiade | Actor |
| Herman Rudin | Mops Volpe |
Technical Credits
| Phil Karlson | Director |
| Jack Baker | Choreography |
| Ralph Berger | Art Director |
| Ed Butterworth | Makeup |
| Sandy Grace | Set Decoration/Design |
| Wilber Hatch | Score Composer |
| Quinn Martin | Producer |
| Paul Monash | Screenwriter |
| Frank T. Smith | Art Director |
| Charles Straumer | Cinematographer |
| Robert L. Swanson | Editor |