Carol Marsh
Role: Susan Graham
David Tomlinson
Role: Nick Martin
Mervyn Johns
Role: Ernest Bennett
Richard Hearne
Role: Professor Pastry
Jimmy Edwards
Role: Dr. Edwards
Peter Hammond
Role: Spencer Stone
Jon Pertwee
Role: Headwaiter
Wilfrid Hyde-White
Role: Dr. B. Jekyll
Peter Haddon
Role: Major Basil Beagle
Geoffrey Sumner
Role: Humphrey Beagle
Zena Marshall
Role: Giselle
Colin Gordon
Role: Chadbeater Longwick
Judith Furse
Role: Mrs. Martin
Edmund Willard
Role: Ezekial
Robert Lamouret
Role: The 'Duck' Man
Henry Kendall
Role: Lord Bruce Carlton
Bill Fraser
Role: Oliver Cromwell
Shirl Conway
Role: Cabaret Star
George Benson
Role: Temporary Waiter
Sandra Dorne
Role: Receptionist
Patricia Raine
Role: Amber
Ronald Adam
Role: Director General of the BBC (uncredited)
Michael Balfour
Role: Barman (uncredited)
Johnny Briggs
Role: BBC Page Boy (uncredited)
Esma Cannon
Role: Autograph Huntress (uncredited)
Cyril Chamberlain
Role: (uncredited)
Andrew Crawford
Role: First BBC Announcer (uncredited)
Valentine Dyall
Role: Man Telling Story at BBC (uncredited)
Danny Green
Role: Liftman (uncredited)
Kenneth Griffith
Role: Nick Martin's BBC Colleague (uncredited)
Anne Gunning
Role: Young Woman (uncredited)
James Hayter
Role: Inn Landlord (uncredited)
Glynis Johns
Role: Miranda Trewella (uncredited)
Michael Medwin
Role: Man Giving BBC Boxing Talk (uncredited)
Hal Osmond
Role: Radio Sound-Effects Man (uncredited)
Brian Oulton
Role: BBC Producer (uncredited)
Wally Patch
Role: BBC Commissionaire (uncredited)
Dennis Price
Role: Lord Byron (archive footage) (uncredited)
Basil Radford
Role: Maj. Bright (uncredited)
Harry Secombe
Role: Alf (uncredited)
Anthony Steel
Role: (uncredited)
David Ward
Role: Ghost (uncredited)
Michael Ward
Role: News Reader (uncredited)
Richard Wattis
Role: Compere of Nick Nack Show (uncredited)
Naunton Wayne
Role: Capt. Early (uncredited)