The plot of the film reprises that of the 1932 version, with James Parker (Douglas) Harry Holt (Danova) and Parker’s daughter Jane (Barnes) on an expedition in Africa in which they encounter Tarzan, a wild man raised by apes. Various adventures ensue.
A native village is robbed, supposedly by natives. Before a man dies, he mentions the name “Slade”. Black colouring is found on his hand so they know it is white people who did it, disguised as blacks. Tarzan arrives, remembering Slade from a year previously as a man who let 3 of his men die and has a grudge against him. A woman (Angie) turns up, Sanchez’ latest woman, flying one of his planes. Later she buzzes Tarzan in his canoe, and crashes the plane so now Tarzan is stuck with her as he goes after Slade. Slade has 3 men and a girlfriend with him. He knows where a diamond mine is and has got his supplies for his trip by stealing them. Tensions run high amongst his men. Kruger is an ex-Nazi and a diamond expert. O’Bannion is an Irish rebel, a drunk and a trouble maker who keeps hassling Dino till Dino decides to kill him but falls foul of a wild animal and quicksand.
Tarzan and Angie lose their canoe but take an overland short cut where he fells some trees into the water to stop Slade’s boat. Tarzan attacks them with arrows but they respond with (stolen) dynamite and Tarzan is injured. He later kills O’Bannion but collapses, needing Angie’s help. Angie is captured trying to get penicillin for Tarzan and the group continue in their boat. Tarzan recovers and follows them to the diamond mine. Toni (Slade’s girlfriend) falls into a trap meant for Tarzan. In the cave, Kruger realises that Slade is more interested in danger than diamonds and tries to kill him but is in turn killed. Slade then goes out to wait for Tarzan with his prepared weapon, a metal noose for garrotting him. There is a final fight between the two on a cliff top.
The idyllic jungle life of Tarzan (Gordon Scott), Jane (Eve Brent) and Tartu (Rickie Sorensen) is interrupted by a drum message telling them of predatory hunters loose in the jungle. Tarzan disrupts the animal-collecting expedition of the hunters, Schroeder (Lesley Bradley) and Rene (Maurice Marsac); he frees a baby elephant whose mother they have killed and then leads the elephant herd against them when they make hostages of Tartu and Cheeta the chimp. Afterwards he warns off two other hunters, Sikes (Saul Gorse) and Lapin (William Keene), seeking to plunder the lost city of Zarbo. He is attacked by their men, but escapes and shadows their party. Aware of Tarzan’s continued presence, the hunters capture his native friend Tyana (Sherman Crothers), and trap the ape man when he tries to free him. Tyana’s tribe rescues the two. Finally, the hunters reach Zarbo, but find it empty of both people and treasure. In a final conflict, Tarzan overcomes the villains, who are then turned over to the authorities by the natives.
Jungle medics Dr. Sturdy (Carl Benton Reid) and his daughter Anne (Jil Jarmyn) are opposed by witch doctor Futa (James Edwards) of the Nagasu tribe, who regards their work as a threat to his own livelihood. Futa incites the tribe to waylay Anne’s fiance Dr. Ken Warwick (Harry Lauter), who is saved by Tarzan (Gordon Scott). Later Tarzan and his adopted son Tartu (Rickie Sorensen) enlist the doctors’ services on behalf of Jane (Eve Brent), suffering from appendicitis. Futa hypnotises Moto (Nick Stewart), a native assistant of Sturdy, to murder Jane, but Tarzan thwarts the plot. Learning that the young Nagasu chief (Roy Glenn) is sick, Tarzan attempts to persuade them to let Sturdy treat them. Seizing his chance, Futa has the ape man taken captive and condemned to death. To restore his own credentials, the witch doctor then undertakes to cure the chief himself, hedging his bets by having his henchman Ramo (Woody Strode) steal medicine from Sturdy. Unfortunately, Ramo purloins a poison by mistake. Freeing himself, Tarzan intervenes and prevents the administration of the poison to the chief; Futa then swallows it himself to demonstrate that there is no harm in it — and dies. Dr. Sturdy is consequently called in, successfully curing the chief.
An airplane crashes in the jungle, stranding passengers Gamage Dean (Yolande Donlan), Diana Penrod (Betta St. John), “Doodles” Fletcher (Wilfrid Hyde-White), Carl Kraski (George Coulouris), and Dick Penrod (Peter Arne). Before the plane slides into a gorge the group is rescued by Tarzan (Gordon Scott), who undertakes to lead them back to civilization. Diana is kidnapped by warriors from Opar under chief Chief Ogonooro (Orlando Martins). The Oparians desire the strangers as sacrifices for their lion god. She is recovered by Tarzan and hunter Tusker Hawkins (Robert Beatty), whose advances Diana rebuffs. Secretely, however, Hawkins is in league with the Oparians, and plans to sell the castaways to the natives for a fortune in ivory. Tarzan, rightly suspecting Hawkins’ untrustworthiness, exposes his treachery. Now openly in league with the natives, the hunter helps them take the white party captive in Tarzan’s absence. The ape man returns to save them before the sacrifice can take place, aided by his chimpanzee ally Cheeta, who sets fire to the native village. He then leads them to the safety of a nearby settlement. Hawkins meets his fate at the hands of the Oparians, to whom Tarzan has signalled his double-dealing by a creative use of jungle drums.
The film contains more echoes of the original Burroughs novels than usual in a Tarzan movie, including the ape man’s allusions to his origin (which follows Burroughs’ version), and the use of Opar, though reducing the romantic lost city described by Burroughs to a generic native village. Tarzan, while retaining the customary film characterization of an inarticulate simpleton, displays considerable shrewdness and resource, foreshadowing the restoration of Burroughs’ original concept of an intelligent, omnicompetent ape man in later movies.
Two men come into the jungle intent on wholesale slaughter of animals to get barrels of animal fat, lion skins and tusks. Tarzan tries to help a baby elephant, one of their first victims. He takes the elephant to an animal doctor and his female assistant who have pitched their tents in the jungle to do business. The hunters turn up and pretend they are photographers and have the doctor escort them to where the animals are. They leave the doctor and start killing animals. His assistant finds out they are evil and goes after them but needs Tarzan’s help when she stumbles into quicksand. He rescues her, and she says she needs a bath so Tarzan throws her into the river.
They reach a tribe who worship animals and who are Tarzan’s friends. However, the tribe hear that animals are being slaughtered and decide to kill the doctor and his assistant as he led them there. Tarzan goes after the villains and they end up getting their just deserts. He arrives back in time to save the doc and his assistant from the lions in the pit they have been thrown into.
Poachers enslave the men of the Lykopo tribe in order to force them to capture bull elephants for their ivory. Lyra, the employer of the poachers tries to have Jane kidnapped but her men fail and burn down Tarzan and Jane’s tree house. Tarzan believes Jane died in the fire and becomes despondent. Lyra has her men capture Tarzan in an attempt to force him to help them herd the elephants. Jane was able to escape the fire and is captured while searching for Tarzan. Once Tarzan sees Jane is alive and well, he is relieved but now he must figure a way to save them both.
After killing Tarzan’s real cousin, Rokov devises a plan to use the diary of Lord Greystoke, Tarzan’s father, to convince Tarzan that Edward, Rokov’s partner is Tarzan’s cousin. Rokov and Tarzan’s cousin, Edward, convince Tarzan that they need to find diamonds that are in Waziri country for national security. Once they get there, Rokov ambushes Tarzan and kills Edwards and the Waziri Witch Doctor and steels the diamonds. The Waziri tribe are very upset and plan to take revenge of the death of the Witch Doctor by sacrificing Jane. Joey, a boy Jane and Tarzan rescued and decided to adopt runs into the jungle in search of the wounded Tarzan in an attempt get Tarzan to save Jane but Joey must face his biggest fears in the jungle.
Melmendi, Queen of the Ashuba tribe has turned down the marriage proposal from Bulam, King of the Yorango tribe. He is very upset and plans to get vengeance on the peaceful Ashuba tribe by getting guns so he can attack the new Queen and her citizens. Radijeck, a prison escapee is quick to negotiate a deal with Bulam. Tarzan was responsible for putting Radijek in prison once. Bulam uses the guns to capture and imprison Melmendi. Somehow, Tarzan must protect Jane from Radijeck and rescue the Queen.
While searching desperately for the kidnapped native girls, Tarzan discovers that the people of Lyolia are dying from a plague. He brings the doctor from Randini to help try to cure the sick people. The Loyolians decide to kidnap both Jane and the nurse, Lola, and use them to repopulate their city. In an attempt to escape, Jane and Lola end up trapped in a tomb that Sengo, the head kidnapper, has sealed. In the meantime the Prince of Lyolia has his high priest imprisoned because he has been unable to cure his son. Tarzan and the Doctor lose the medicine in the jungle. Tarzan finds out that Jane and Lola are in a sealed tomb and he must find them before their air is used up.
