Buck Rand is desperate to have Boy perform in his circus, as he believes the boy is the key to drawing large crowds. He hires a pilot, who he threatens with harm, to fly him and his team out of the jungle. Tarzan, suspicious of Rand's intentions, follows them to New York City.
Upon arriving in New York, Boy is immediately placed in the circus and forced to perform dangerous stunts. Tarzan and Jane seek legal help to regain custody of Boy, but they are met with resistance from Rand and his team.
In a fit of rage, Tarzan becomes violent in the courtroom and is taken to jail. While in jail, Tarzan discovers his animal instincts have not left him as he befriends some of the animals living in the city zoo.
Meanwhile, the pilot's girlfriend, who was initially skeptical of Tarzan and his abilities, becomes convinced of his sincerity and helps him escape from jail. Tarzan and the pilot's girlfriend then embark on a mission to rescue Boy from the circus.
The rescue involves Tarzan, the elephants from the circus, and a thrilling chase through the streets of New York City. In the end, Boy is reunited with Tarzan and Jane, and the villains are brought to justice.
Throughout the film, Tarzan struggles to adapt to the new surroundings and the modern city lifestyle. He is often confused by everyday things such as elevators, telephones, and automobiles. However, with his strength and determination, Tarzan is able to overcome any obstacle in his way.