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 | Mario Bava | Screenplay |
| Writing | Sandro Continenza | Screenplay |
| Writing | Duccio Tessari | Screenplay |
| Directing | Mario Bava | Director |
| Camera | Mario Bava | Director of Photography |
| Writing | Sandro Continenza | Story |
| Writing | Duccio Tessari | Story |
| Writing | Franco Prosperi | Story |
| Directing | Franco Prosperi | First Assistant Director |
| Directing | Bona Magrini | Script Supervisor |
| Art | Tony Sarzi-Braga | Assistant Production Design |
| Art | Giuseppe Ranieri | Assistant Production Design |
| Camera | Ubaldo Terzano | Camera Operator |
| Camera | Giuseppe Berta | Assistant Camera |
| Camera | Luciano Brebbia | Assistant Camera |
| Camera | Enrico Santelli | Still Photographer |
| Sound | Luigi Puri | Sound |
| Sound | Eugenio Fiori | Boom Operator |
| Sound | Adolfo Fabrizi | Sound Recordist |
| Costume & Make-Up | Silvano Giusti | Assistant Costume Designer |
| Costume & Make-Up | Renzo Francioni | Assistant Makeup Artist |
| Production | Giorgio Baldi | Unit Manager |
| Production | Dino Di Salvo | Production Secretary |
| Production | Giovanna Pellegrino | Production Secretary |
| Production | Alfredo Petri | Production Secretary |
| Production | Ernesto Poli | Administration |
| Costume & Make-Up | Maria Luisa Onorati | Seamstress |
| Costume & Make-Up | Valeria Sponsali | Seamstress |
| Editing | Lina Caterini | Assistant Editor |
| Sound | Tonino Cacciottolo | Foley Artist |
| Sound | Fausto Ancillai | Sound Mixer |
| Sound | Nino Renda | Sound Mixer |
| Camera | Joe D'Amato | Camera Operator |
| Writing | Mario Bava | Story |
| Writing | Franco Prosperi | Screenplay |
| Sound | Armando Trovajoli | Original Music Composer |
| Editing | Mario Serandrei | Editor |
| Art | Franco Lolli | Production Design |
| Costume & Make-Up | Mario Giorsi | Costume Design |
| Costume & Make-Up | Franco Palombi | Makeup Artist |
| Costume & Make-Up | Nicla Palombi | Hairstylist |
| Production | Danilo Marciani | Production Manager |
