Bud Spencer plays Banana Joe, a brawny yet friendly man who lives in a small rainforest village called Amantido with a huge number of his own children and regularly delivers bananas to a South American river port (hence his name). One day, the henchmen of a local gangster boss named Torsillo come ashore in Amantido to initiate the construction a banana processing plant. Of course, Joe (in typical direct-approach manner) evicts the goons, who promptly return to their boss. Torsillo finds out that Joe is trading bananas without a license and decides to exploit it. Upon his next delivery, Joe is apprehended by the police and given the choice of either acquiring a legal license or getting his boat taken away and himself arrested for illegal shipment. Joe travels to the nearest city, which to him is a new world, as he grew up in the rainforest.