Bij zijn terugkeer van de strijd in de vorige film komt de grote krijger Hercules erachter dat zijn geliefde, Daianara, haar verstand heeft verloren. Volgens het orakel Medea is Dianara's enige hoop de Steen der Vergetelheid die diep in het rijk van Hades ligt. Hercules, met twee metgezellen, Theseus en Telemachus, begint aan een gevaarlijke zoektocht naar de steen, terwijl hij niet weet dat Dianara's voogd, koning Lico, degene is die verantwoordelijk is voor haar toestand en beraamt plannen om het meisje voor zichzelf te hebben als zijn bruid.
Nee, helaas is Ercole al centro della terra nog niet beschikbaar op Netflix in Nederland.
| Production | Achille Piazzi | Producer |
| Writing | Sandro Continenza | Screenplay |
| Writing | Duccio Tessari | Screenplay |
| Directing | Mario Bava | Director |
| Writing | Mario Bava | Screenplay |
| Camera | Mario Bava | Director of Photography |
| Directing | Bona Magrini | Script Supervisor |
| Costume & Make-Up | Renzo Francioni | Assistant Makeup Artist |
| Art | Giuseppe Ranieri | Assistant Production Design |
| Camera | Ubaldo Terzano | Camera Operator |
| Camera | Enrico Santelli | Still Photographer |
| Sound | Eugenio Fiori | Boom Operator |
| Sound | Tonino Cacciottolo | Foley Artist |
| Production | Giovanna Pellegrino | Production Secretary |
| Production | Ernesto Poli | Administration |
| Writing | Duccio Tessari | Story |
| Camera | Giuseppe Berta | Assistant Camera |
| Production | Giorgio Baldi | Unit Manager |
| Production | Alfredo Petri | Production Secretary |
| Costume & Make-Up | Maria Luisa Onorati | Seamstress |
| Writing | Sandro Continenza | Story |
| Production | Dino Di Salvo | Production Secretary |
| Writing | Franco Prosperi | Story |
| Art | Tony Sarzi-Braga | Assistant Production Design |
| Sound | Adolfo Fabrizi | Sound Recordist |
| Directing | Franco Prosperi | First Assistant Director |
| Camera | Luciano Brebbia | Assistant Camera |
| Sound | Fausto Ancillai | Sound Mixer |
| Editing | Lina Caterini | Assistant Editor |
| Sound | Nino Renda | Sound Mixer |
| Sound | Luigi Puri | Sound |
| Costume & Make-Up | Silvano Giusti | Assistant Costume Designer |
| Costume & Make-Up | Valeria Sponsali | Seamstress |
| Camera | Joe D'Amato | Camera Operator |
| Writing | Mario Bava | Story |
| Production | Danilo Marciani | Production Manager |
| Costume & Make-Up | Mario Giorsi | Costume Design |
| Costume & Make-Up | Franco Palombi | Makeup Artist |
| Editing | Mario Serandrei | Editor |
| Art | Franco Lolli | Production Design |
| Sound | Armando Trovajoli | Original Music Composer |
| Writing | Franco Prosperi | Screenplay |
| Costume & Make-Up | Nicla Palombi | Hairstylist |
