Rodrigo Díaz de Vivar, “Mio Cid”, is in love with Jimena, but the Count of Oviedo, his father, challenges him to a duel and is killed. He before him curses Rodrigo, that if he marries Jimena, he will lose his manly faculties. And, in fact, when he gets married, Rodrigo becomes effeminate.
| Directing | Angelino Fons | Director |
| Writing | Juan José Alonso Millán | Story |
| Writing | Juan José Alonso Millán | Screenplay |
| Production | José Frade | Producer |
| Editing | Mercedes Alonso | Editor |
| Art | José Luis Galicia | Set Decoration |
| Costume & Make-Up | Gumersindo Andrés | Costume Design |
| Costume & Make-Up | Mariano García Rey | Makeup Artist |
| Costume & Make-Up | Nieves Sánchez | Hairstylist |
| Production | José Salcedo | Production Manager |
| Directing | Juan Ignacio Galván | Assistant Director |
| Crew | Fernando Pérez | Special Effects |
| Crew | Pablo Pérez | Special Effects |
| Camera | Manuel Martínez | Still Photographer |
| Lighting | Julio Romera | Gaffer |
| Camera | Antonio Sáiz Palazón | Camera Operator |
| Editing | Marisa Hernández | Assistant Editor |
| Editing | María Dolores Laguna | Assistant Editor |
| Directing | Margarita Fernández | Script Supervisor |
| Camera | José García Galisteo | Director of Photography |
| Sound | Teddy Bautista | Original Music Composer |
| Art | Félix Rodríguez | Property Master |
