Stephen Roberts Director William Powell Dr. Lawrence Bradford Actor Jean Arthur Paula Bradford Actor James Gleason Inspector Corrigan Actor Eric Blore Stokes Actor Robert Armstrong Nick Martel Actor Lila Lee Miss Prentiss Actor Grant Mitchell John Summers Actor Erin O'Brien-Moore Mrs. Summers Actor Ralph Morgan Leroy Hutchins Actor Lucile Gleason Mrs. Hutchins Actor Frank M. Thomas Mike North Actor Frank Reicher Henry Strand Actor Charles Richman Mr. Curtis Actor John Sheehan Bert "Murphy" Murph Actor Paul Fix Lou Pender Actor Johnny Arthur Mr. Frankenstein Actor Spencer Charters Dr. Bunting Actor James Donlan Taxi Driver Actor Dorothy Granger Fill-in Receptionist Actor Stanley Blystone Police Radio Operator Actor Syd Saylor Detective Actor Rollo Lloyd North's 'Landlord' Actor Charles McMurphy Actor Samuel Hayes Race Announcer Actor Anthony Veiller Screenwriter Edward Kaufman Producer J. Roy Hunt Cinematographer Arthur Roberts Film Editing Van Nest Polglase Art Director Bernard Newman Costume Design