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