Roberto Maldi, a young scientist, is trying to find a serum capable of giving courage but he unwittingly invents a serum which transforms any man in a womanizer. His boss scents a good business and wants to produce the serum on industrial basis, but Roberto does not agree.

Alberto loves Maria, daughter of Arturo, a rich owner of boats, his love is reciprocated by the girl and has the approval of her father.

Roaming the vast jungles of Congo with his best friend, Bongo the gorilla, Antonio della Buffas, a mysterious man whom the natives call the "white monkey", is utterly unaware that he is the long-lost son of a wealthy explorer. Then, three opportunists manage to capture and bring the white savage to civilisation, bent on getting their hands on his immense fortune.