Upon his return from battle in the previous film, the great warrior Hercules learns that his lover, Daianara, has lost her senses. Acording of the oracle Medea, Dianara's only hope is the Stone of Forgetfulness which lies deep in the realm of Hades. Hercules, with two companions, Theseus and Telemachus, embarks on a dangerous quest for the stone, while he is unaware that Dianara's guardian, King Lico, is the one responsible for her condition and plots to have the girl for himself as his bride upon her revival.
Unfortunately the movie Hercules in the Haunted World is not yet available on HBO Max.
| 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 |
