The movie takes place in the West Side of New York, in the late 1950s.The Jets are a teenage gang of American boys determined not only to check but to destroy the growth of Puerto Rican population and influence on their block. They are opposed by a Puerto Rican gang, the Sharks, led by Bernardo.
In the entirely dance sene, the members of the two rival gangs provoke each other. A fight breaks out between them, but it’s broken up by the arrival of two cops. After the police has got rid of the Puerto Ricans, Riff, the leader of the Jets, informs his gang that he will challenge Bernardo to a decisive rumble that night at a dance. The Jets are convinced of their invincibility, they sing the Jet song.
Riff tries to talk his friend Tony into being his lieutenant for the challenge. Tony, who is the co-founder of the Jets, has been growing away from the gang and is now working at Doc’s, the neighborhood’s drugstore. Tony reluctantly agrees to meet Riff at the dance and sings about his feelings the song he sings is called something’s comming i think.
The Jets, led by Riff and Graziella, and the Sharks, led by Bernardo and his girl Anita, meet at the dance in the neighborhoood gym, where in choreography their violent hostility to each other is reflected when they dance at the gym.
During the frenzied dancing, Tony meets the lovely Maria. She is Bernardo’s sister who has just arrived from Puerto Rico to marry Chino. To both Tony and Maria, it’s love at first sight. But Bernardo stops them from dancing together and insists that Chino takes Maria home.
Later the challenge is made for a war council to decide on weapons for the rumble. Meanwhile, Tony walks through the streets, thinking only of his new love, Maria . On a tenement rooftop, Bernardo, his girlfriend Anita and their friends joyfully sing about the relative quality of life among Puerto Ricans in New York. At midnight, the Sharks boys go off to the war council, much to Anita’s annoyance at Bernardo.
Meanwhile, Tony finds the building where Maria lives and he climbs up her fire escape to meet her. They sing of their lovetonight. They plan to meet in the bridal shop where Maria is employed the next day.
At Doc’s drugstore, Riff and the Jets are warned by Krupke, a cop, no to cause any trouble on the block. When he leaves, the Jets start mocking at the way they are treated by the police and adults in general, officer Kurpuetre .
Later, the Sharks arrive and the two leaders name the place, time and weapons for a big “rumble” deciding which one of the two gangs will be dominant in the neighborhood. Through Tony’s influence, an agreement is reached to have a boy represent each of the two gangs, and have them fight out to a finish the following day.
The next day at the bridal shop, Maria tells her fellow workers how wonderful it feels to be in lovei feel pterry, as she prepares for Tony’s arrival (her friends assume she is singing about Chino, her fiance).
After the place is closed to customers, Tony meets with Maria and makes a promise to stop the fight. They improvise a mock-marriage, with dress dummies as wedding attendants, they sing one hand one heart.
In the quintet version of tonight, everyone sings of their expectation that it will be a wonderful, glorious and victorious night Under the highway, the fist-fight is about to begin when Tony arrives. He tries to stop the fight and offers his friendship to Bernardo, but Bernardo only insults Tony and pushes him away. Riff steps in and strikes Bernardo. In the fight that follows, switchblade knifes appear and Riff is accidentally stabbed by Bernardo. Tony reflexively takes Riff’s knife and kills Bernardo in the rumble. As police sirens come nearer, the gangs run off, leaving behind the dead bodies of their two leaders.
Later Chino arrives at Maria’s appartment and tells her about the rumble and that Tony has killed her brother. Enraged, Chino realises that Maria has been seeing Tony and runs away.
Tony climbs through Maria’s window and begs her forgiveness so he can then go to the police. However, s