Anthony “Tony” Manero is a 19-year-old Italian American from the Bay Ridge neighborhood of Brooklyn, New York. He lives with his parents, grandmother, and younger sister, and works at a dead-end job in a small hardware store. To escape his day-to-day life, Tony goes to 2001 Odyssey, a local disco club, where he is king of the dance floor and receives the admiration and respect he longs for. Tony has four close friends: Joey, Double J, Gus, and Bobby C. A fringe member of his group of friends is Annette, a neighborhood girl who longs for a more sexual relationship with Tony.
Tony and his friends ritually stop on the Verrazano–Narrows Bridge to clown around. The bridge has special significance for Tony as a symbol of escape to a better life on the other side – in more suburban Staten Island.
Tony agrees to be Annette’s partner in an upcoming dance contest, but her happiness is short-lived when Tony is mesmerized by another woman at the club, Stephanie Mangano, whose dancing skills exceed Annette’s. Although Stephanie rejects Tony’s advances, she eventually agrees to be his partner in the dance competition, provided that their partnership remains professional.
Tony’s older brother, Frank Jr., who was the pride of the family since he was ordained a Roman Catholic priest, brings despair to their parents and grandmother when he tells them he quit the priesthood. Tony shares a warm relationship with Frank Jr., but feels pleased that he, Tony, is no longer the black sheep of the family. Frank, Jr. tells Tony that he never wanted to be a priest and only did it to make their parents happy. Frank Jr. encourages Tony to do something with his dancing.
While on his way home from the grocery store, Gus is attacked by a gang and hospitalized. He tells Tony and his friends that his attackers were the Barracudas. Meanwhile, Bobby C. has been trying to get out of his relationship with his devout Catholic girlfriend, Pauline, who is pregnant with his child. Facing pressure from his family and others to marry her, Bobby asks Frank Jr. if the Pope would grant him dispensation for an abortion. When Frank tells him such a thing would be highly unlikely, Bobby’s feelings of desperation increase.
Eventually, the group gets their revenge on the Barracudas, and crash Bobby C’s car into their hangout. Tony, Double J, and Joey get out of the car to fight, but Bobby C. takes off when a gang member tries to attack him in the car. When the group visit Gus in the hospital, they are angry when he tells them that he may have identified the wrong gang. Later, Tony and Stephanie dance at the competition and end up winning first prize. However, Tony believes that a Puerto Rican couple performed better, and that the judges’ decision was racially motivated. He gives the Puerto Rican couple his trophy and reward money, and leaves with Stephanie. Once outside in a car, Tony tries to force himself on Stephanie, but she resists and runs from him.
Tony’s friends come to the car along with an intoxicated Annette. Joey says she has agreed to have sex with everyone. Tony tries to lead her away, but is subdued by Double J and Joey, and sullenly leaves with the group in the car. Double J and Joey rape an intoxicated Annette. Bobby C. pulls the car over on the Verrazano-Narrows Bridge for their usual cable-climbing antics. Instead of abstaining as usual, Bobby performs stunts more recklessly than the rest of the gang. Realizing that he is acting recklessly, Tony tries to get him to come down. Bobby’s strong sense of despair, the situation with Pauline, and Tony’s broken promise to call him earlier that day all lead to a suicidal tirade about Tony’s lack of caring before Bobby slips and falls to his death in the water below.
Disgusted and disillusioned by his friends, his family, and his life, Tony spends the rest of the night riding the subway into Manhattan. Morning has dawned by the time he appears at Stephanie’s apartment. He apologizes for his bad behavior, telling her that he plans to relocate from Brooklyn to Manhattan to try and start a new life. Tony and Stephanie salvage their relationship and agree to be friends.