 Edward G. RobinsonDr. T.S. Clitterhouse | Dr. T.S. Clitterhouse |
 Claire TrevorJo Keller | Jo Keller |
 Humphrey Bogart'Rocks' Valentine | 'Rocks' Valentine |
 Allen JenkinsOkay | Okay |
 Donald CrispPolice Inspector Lewis Lane | Police Inspector Lewis Lane |
 Gale PageNurse Randolph | Nurse Randolph |
 Henry O'NeillJudge | Judge |
 John LitelMr. Monroe, Prosecuting Attorney | Mr. Monroe, Prosecuting Attorney |
 Thurston HallGrant | Grant |
 Ward BondTug | Tug |
 Ronald ReaganRadio Announcer (voice) (uncredited) | Radio Announcer (voice) (uncredited) |
| MMary FieldMillie - Mrs. Updyke's Maid (uncredited) | Millie - Mrs. Updyke's Maid (uncredited) |
 Maxie RosenbloomButch | Butch |
 Vladimir SokoloffPopus | Popus |
 Bert HanlonPat | Pat |
 Curt BoisRabbit | Rabbit |
 Billy WayneCandy | Candy |
 Robert HomansLt. Johnson | Lt. Johnson |
 Irving BaconForeman of Jury | Foreman of Jury |
| JJohn AlbanGuest (uncredited) | Guest (uncredited) |
| FFrank AnthonyGambler in Room 920 (uncredited) | Gambler in Room 920 (uncredited) |
 Wade BotelerCaptain MacLevy (uncredited) | Captain MacLevy (uncredited) |
 Sidney BraceyPolice Chemist (uncredited) | Police Chemist (uncredited) |
| JJohn BreenSpectator at Robbery (uncredited) | Spectator at Robbery (uncredited) |
 Georgia CaineMrs. Frederick R. Updyke (uncredited) | Mrs. Frederick R. Updyke (uncredited) |
 Romaine CallenderRoberts - Updyke's Butler (uncredited) | Roberts - Updyke's Butler (uncredited) |
 Glen CavenderAlarm Company Clerk (uncredited) | Alarm Company Clerk (uncredited) |
| LLoia CheaneyNurse Conner (uncredited) | Nurse Conner (uncredited) |
| BBud CokesCourtroom Spectator (uncredited) | Courtroom Spectator (uncredited) |
| HHal CraigDetective Getting Rocks' Fingerprints (uncredited) | Detective Getting Rocks' Fingerprints (uncredited) |
