In 2006, Rocky Balboa (Sylvester Stallone) has been retired from boxing for twenty years and lives a quiet life as a widower. His wife Adrian Pennino Balboa (Talia Shire) had died from cancer four years earlier. He runs a small but very successful Italian restaurant named after her, where he regales his patrons with stories of his past. He also battles personal demons involving his grief over Adrian's death, the changing times, and his eroding relationship with his son Robert (Milo Ventimiglia), a struggling corporate employee. Paul "Paulie" Pennino (Burt Young), Rocky's brother-in-law and best friend, continues to keep by his side, but is tired of reliving the past.
Following the fight at the end of Rocky, in which Apollo Creed has successfully defended his heavyweight title in a split decision, he and Rocky are taken to the same hospital. Apollo challenges Rocky to a rematch, but Rocky declines and announces his retirement. His girlfriend Adrian supports this choice, as do his doctors, who reveal he will require surgery for a detached retina, which could lead to permanent blindness. After Rocky is discharged from the hospital, he enjoys the benefits of his life's changes: Rocky's new fame attracts an agent who sees Rocky as a potential endorsement and sponsorship goldmine, and his sudden wealth encourages him to propose to Adrian. She happily accepts, and they marry in a small ceremony. Soon after, Rocky and Adrian happily learn that Adrian is pregnant.
In the four and a half years since winning the world heavyweight title, Rocky Balboa has had a string of successful title defenses (10) and has seen his fame, wealth and celebrity increase. While unveiling a statue of himself at the steps of the Philadelphia Museum of Art, Rocky is publicly challenged by James "Clubber" Lang (Mr. T), a ferocious new boxer rapidly climbing the ranks. Lang accuses Rocky of intentionally accepting challenges from lesser opponents, and after making a sexual remark toward Rocky's wife Adrian (Talia Shire), his challenge is accepted.
In 1985, Ivan Drago (Lundgren), a muscular 6-foot-5, 261-pound Soviet boxer, arrives in the United States with his wife Ludmilla (Nielsen), and a team of trainers from the USSR and Cuba. His manager, Nicolai Koloff (Pataki), takes every opportunity to promote Drago's athleticism as a hallmark of Soviet superiority. Motivated by patriotism and an innate desire to prove himself, Apollo Creed (Weathers) challenges Drago to an exhibition bout. Rocky (Stallone) has reservations, but agrees to train Apollo despite his misgivings about the fight. He asks Apollo whether the fight is against the Russian, or "you against you".
Shortly after Rocky Balboa's victory over Ivan Drago in Moscow, he, his wife Adrian, his brother-in-law Paulie, and his trainer Tony "Duke" Evers return to the U.S., where they are greeted by Rocky's son Robert. At a press conference, boxing promoter George Washington Duke attempts to goad Rocky into fighting his boxer Union Cane for the World Heavyweight Championship in Tokyo, but Rocky declines the offer. Upon returning home, it is discovered that Paulie unknowingly had Rocky sign a "power of attorney" over to Rocky's accountant, who had squandered all of his money on real estate deals gone sour; in addition, the accountant had failed to pay Rocky's taxes over the past six years, and the mansion is discovered to be unpaid by $400,000.
Charley Davis, against the wishes of his mother, becomes a boxer. As he becomes more successful the fighter becomes surrounded by shady characters, including an unethical promoter named Roberts, who tempt the man with a number of vices. Charley finds himself faced with increasingly difficult choices.
Corrupt, flamboyant Atlantic City police detective Rick Santoro (Nicolas Cage) attends a boxing match at Gilbert Powell's (John Heard) Atlantic City Arena between heavyweight champion Lincoln Tyler (Stan Shaw) and challenger Jose Pacifico Ruiz. He meets up with his best friend since childhood, Kevin Dunne (Gary Sinise), who is a US Navy Commander working with the Department of Defense to escort Defense Secretary Charles Kirkland (Joel Fabiani) and Powell at the fight after a trip to Norfolk, Virginia. As the first round begins, Dunne is distracted by an attractive redhead named Serena (Jayne Heitmeyer) who wears a ruby ring, and leaves his seat, which is then taken by Julia Costello (Carla Gugino), a mysterious woman with platinum blonde hair and a white satin suit.
Adolescent, entraîné par un camarade, il entre au service de la Camorra. Un jour, pour échapper à la police, il se réfugie dans une salle d'entraînement, l'Excelsior. C'est la planche de salut pour Michele qui découvre un nouvel univers, la boxe, sous l'autorité du vieux coach Sabatino. Lors de chaque combat, de chaque round, c'est sa propre survie que le jeune homme remet en jeu. Toute nouvelle victoire l'éloigne, pas à pas, des ennuis et l'amène à grandir, à trouver une certaine stabilité.
Hillary Kramer (Streisand), a successful perfume magnate awakes one morning to find that her accountant has robbed her blind and left for South America. Going through all of her remaining assets she finds a boxer, purchased as a tax write off. She decides to take Eddie "Kid Natural" Scanlon (Ryan O'Neal) who is much more at home giving driving lessons, into the ring and use him as her key to riches. Eddie thinks this will only get him killed and resists.
Sarah Wurble's husband Willy is the larceny-inclined manager of an illiterate, and very religious boxer from Tennessee named Danny. Gifted with a powerful punch and a nickname that gives the film its title, Danny mistakenly believes he killed a man defending himself in a street brawl, and goes on the lam as a prizefighter.
Former Irish pugilist & Provisional IRA member Danny Flynn (Daniel Day-Lewis) returns home to Belfast from a 14-year stint in prison at the age of 32. Weary of the unbroken cycle of violence in Northern Ireland, he attempts to settle down and live in peace. After meeting his drink-sodden old trainer Ike (Ken Stott), Danny starts up a non-sectarian boxing club for boys in an old gymnasium. While fixing up the old building, however, he runs across a cache of Semtex hidden underneath the stage. He throws the cache into the river.