Fred Wilson (Charles Grodin), an executive of the Petrox Oil Company, forms an expedition based on infrared imagery which reveals a previously undiscovered Indian Ocean island hidden by a permanent cloud bank.
Wilson believes the island has a huge deposit of oil. Jack Prescott (Jeff Bridges), a primate paleontologist who wants to see the island for himself, stows away on the expedition's vessel.
Prescott reveals himself when he warns the crew the cloud bank may be caused by an unknown beast. Wilson orders Prescott locked up, claiming that he is really a spy from a rival oil company.
While escorted to lock-up, Prescott spots a life raft which carries the beautiful and unconscious Dwan (Jessica Lange). Wilson conducts a thorough background check on Prescott and realizes he is telling the truth.
He appoints Prescott the expedition's official photographer and requests that he be present when Dwan revives because of his medical background. Upon waking, Dwan says she is an aspiring actress who was aboard a director's yacht which suddenly exploded.
Upon arriving at the island, the team discovers a primitive tribe of natives who live within the confines of a gigantic wall, built to protect them from a mysterious god known as Kong.
The team finds that while there is a large deposit of oil, it is of such low quality that it is unusable. Later that night, the natives kidnap Dwan, drug her, and offer her as a sacrifice to Kong.
A gigantic ape grabs Dwan from the altar and departs back into the jungle. Although an awesome and terrifying sight, the soft-hearted Kong quickly becomes tamed by Dwan, whose rambling monologue calms and fascinates the monstrous beast.
After Dwan falls into mud, Kong takes Dwan back to a waterfall to wash her and dry her with great gusts of his warm breath. In the meantime, Prescott and First Mate Carnahan (Ed Lauter) lead a rescue mission to save Dwan.
The rescue party encounters Kong while crossing a log bridge, and Kong rolls the huge log, sending Carnahan and most of the rest of the sailors falling to their deaths.
Prescott and Boan are the only ones to survive. While Boan returns to the village, Prescott continues looking for Dwan. Kong takes Dwan to his lair, where she finally realizes that he is no threat to her.
A giant snake appears and attacks them, and while Kong is fighting and killing the snake, Prescott escapes with Dwan. Kong chases them back to the native village.
There he falls into a pit trap and is overcome by chloroform. When Wilson learns the oil cannot be refined, he decides to transport Kong to America as a promotional gimmick for Petrox.
When they reach New York City, Kong is put on display, bound in chains with a large crown on his head. When Kong sees a group of reporters pushing and shoving Dwan for interviews, the ape breaks free of his bonds, roaring at the crowd as panic ensues.
People are trampled as Kong walks through the crowd, including Wilson, who is completely flattened by the ape's foot. Prescott and Dwan flee across the Queensboro Bridge to Manhattan while Kong pursues them.
They take refuge in an abandoned Manhattan bar. Prescott notices a similarity between the Manhattan skyline (notably the World Trade Center Twin Towers) and the mountainous terrain of Kong's island.
He runs downstairs to call the mayor's office and tells them to let Kong climb to the top of the World Trade Center where he can be safely captured. Kong discovers Dwan through the window of the bar and grabs her, then makes his way to the World Trade Center with Jack and the National Guard in pursuit.
In the climax, Kong climbs the South Tower of the World Trade Center. After being attacked by men with flamethrowers while standing on the roof, Kong flees by leaping across to the North Tower.
He rips pieces of equipment from the roof and throws them at the men. One of the objects, a tank filled with flammable material, explodes, killing the men. Four military helicopters are sent in to attack Kong and he fights them, destroying two.
He is then shot and hit repeatedly by gunfire while Dwan pleads for them to stop. The fatally injured Kong falls from the roof to the World Trade Center plaza, where he dies from his injuries. Dwan rushes down to comfort him and with tears in her eyes watches him take his last breath.
An enormous crowd gathers around the ape while Dwan is bombarded by a sea of photographers. Jack fights his way through the crowd to get to Dwan but stops short as she is taken by reporters and journalists while Kong lies dead in a pool of blood and broken concrete.