Jane Parker's cousins try to kidnap the jungle king to get their hands on her inheritance.

Noble-born English woman Jane Parker lives with her wild man sweetheart, Tarzan, in a tree-top hideaway deep in the heart of the African jungle. Jane and Tarzan's home is equipped with running water, an elevator operated by an elephant and a monkey-powered fan. While Jane and Tarzan enjoy their peaceful life, Jane's relatives from England, Rita and her brother Eric, arrive in Africa intent on finding Jane and taking her back to England. Rita and Eric commission the nefarious Captain Fry to lead them to Jane so that they can tell her that she must go to London to sign legal papers relating to her recently deceased uncle's bequest. Captain Fry, an animal hunter, initially denies Eric and Rita's request because he knows the dangers involved in such a trek, but he eventually agrees to escort them in the hope of finding and capturing the infamous great white ape and exporting it to London. Accompanied by his bumbling assistant, Rawlins, and a group of navigating jungle natives, led by Bomba, Fry begins his journey. Soon after embarking on the trip, the party is attacked by the Ganeloni tribe, and Bomba's men desert. While the expedition camps out in a village, Tarzan and Cheetah, his chimpanzee friend, quietly enter their camp and release a number of caged monkeys. Tarzan then returns home, where Jane notices evidence of his having come into contact with white people and asks to be taken to them. Happy to see her relatives, Jane invites them to the treehouse for a meal, and while Tarzan collects food for the feast, Eric and Rita urge Jane to return to London with them. Jane initially objects to leaving Tarzan, but she eventually agrees to go, promising Tarzan she will return as soon as possible. Tarzan takes the news bitterly, but when she insists on spending a day with him before leaving, he is assured of her true feelings for him. Meanwhile, Fry's evil designs upon Tarzan become clear as he arranges to capture him and double-cross Rita and Eric. When the good-hearted Rawlins attempts to foil Fry's plans, Fry kills him and leads Tarzan into a trap by infuriating him with a lie about Jane's plans to stay away forever. Fry persuades Tarzan to enter a cage of his own will by claiming that it is Jane's wish that he do so. However, when Tarzan hears the approach of warriors, he manages to free himself with the help of two elephants. He then rushes to rescue Jane, Eric and Rita, who are being prepared for sacrifice by natives who ambushed them on the trail. After sounding an ape-call that summons elephants to their rescue, Tarzan exposes Fry as a villain and drives him into swampy waters, where he meets his death. Grateful for having been rescued, Rita and Eric inform Jane that their mission was a ruse and that she was not needed in England after all. Jane then bids her relatives farewell and returns to live with Tarzan.