Lucita has been locked away in a convent by her family in order to keep her away from her lover, Esteban. The pair make plans to elope, but Esteban is accused of heresy before Lucita can escape. Hiding in the convent, Esteban discovers the horrifying depravity of the covent's abbess, Sister Incarnation. Can Esteban rescue his love from this madhouse before the inquisitor discovers what is going on and has everyone executed?
Unfortunately the movie The Sinful Nuns of Saint Valentine is not yet available on HBO Max.
| Writing | Sergio Grieco | Screenplay |
| Writing | Max Vitali | Writer |
| Writing | Sergio Grieco | Story |
| Directing | Sergio Grieco | Director |
| Editing | Mario Gargiulo | Editor |
| Costume & Make-Up | Cesare Paciotti | Makeup Artist |
| Directing | Mario Garriba | Assistant Director |
| Camera | Angelo Modugno | Assistant Camera |
| Writing | Gino Mordini | Story |
| Camera | Adolfo Troiani | Camera Operator |
| Production | Massimo Alberini | Production Manager |
| Sound | Vittorio Trentino | Sound Engineer |
| Costume & Make-Up | Carlo Gentili | Costume Design |
| Camera | Lino Galeassi | Assistant Camera |
| Production | Gino Mordini | Producer |
| Writing | Victor Hugo | Theatre Play |
| Camera | Roberto Nicosia | Still Photographer |
| Art | Luchino Oltrona Visconti | Assistant Production Design |
| Sound | Coriolano Gori | Original Music Composer |
| Camera | Emore Galeassi | Director of Photography |
| Production | Ulderico Arditi | Production Secretary |
| Art | Antonio Visone | Production Design |
| Costume & Make-Up | Maria Miccinilli | Hairstylist |
| Directing | Massimo Carocci | Assistant Director |
| Production | Sergio Bollino | Production Manager |
