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 | Robert Louis Stevenson | Novel |
| Writing | Milton Subotsky | Screenplay |
| Production | Max Rosenberg | Producer |
| Production | Milton Subotsky | Producer |
| Editing | Peter Tanner | Editor |
| Sound | Carl Davis | Original Music Composer |
| Production | Ronnie Curtis | Casting |
| Costume & Make-Up | Harry Frampton | Makeup Artist |
| Costume & Make-Up | Peter Frampton | Makeup Artist |
| Directing | Al Burgess | First Assistant Director |
| Sound | Buster Ambler | Sound Mixer |
| Sound | Michael P. Redbourn | Sound Editor |
| Camera | Moray Grant | Director of Photography |
| Costume & Make-Up | Joyce James | Hairstylist |
