Christopher Lee stars in this Amicus production of “Dr. Jekyll & Mr. Hyde” where the names have been changed to Dr. Marlowe and Mr. Blake. Lee as Dr. Marlowe experiments with intravenous drugs that are suppose to release inner inhibitions. So comes forth Mr. Blake (also Lee) who gets more monstrous with each transformation. Peter Cushing plays his friend and colleague, Dr. Utterson.
| Directing | Stephen Weeks | Director |
| Writing | Milton Subotsky | Screenplay |
| Writing | Robert Louis Stevenson | Novel |
| Production | Max Rosenberg | Producer |
| Production | Milton Subotsky | Producer |
| Sound | Buster Ambler | Sound Mixer |
| Costume & Make-Up | Harry Frampton | Makeup Artist |
| Editing | Peter Tanner | Editor |
| Directing | Al Burgess | First Assistant Director |
| Sound | Michael P. Redbourn | Sound Editor |
| Production | Ronnie Curtis | Casting |
| Sound | Carl Davis | Original Music Composer |
| Costume & Make-Up | Peter Frampton | Makeup Artist |
| Camera | Moray Grant | Director of Photography |
| Costume & Make-Up | Joyce James | Hairstylist |
