In 1980, Cuban refugee Tony Montana (Al Pacino) arrives in Miami during the Mariel boatlift. He, along with his best friend Manny Ribera (Steven Bauer), and their friends and associates Angel (Pepe Serna) and Chi-Chi (Ángel Salazar), are sent to "Freedom Town," a refugee camp. In exchange for hitting a former Cuban government official at the request of cocaine trafficking tycoon Frank Lopez (Robert Loggia) in revenge for torturing his brother to death, the group is released from Freedom Town and given green cards. On the outside, they are offered a deal by Frank's henchman Omar Suarez (F. Murray Abraham) to buy cocaine from Colombian dealers. The deal falls through and Angel is dismembered with a chainsaw by the Colombians, in front of a horrified Tony. Manny and Chi-Chi storm the apartment before the same fate befalls Tony, and the Colombians are killed. Suspecting that Omar betrayed them, Tony and Manny insist on personally giving Frank the money and drugs retrieved from the deal. Impressed, Frank hires Tony and Manny. During their meeting, Tony meets, and is instantly attracted to, Elvira Hancock (Michelle Pfeiffer), Frank's trophy wife.
Months later, Tony visits his mother Georgina (Míriam Colón), and younger sister, Gina (May Elizabeth Mastrantonio), of whom he is fiercely protective. His mother is appalled at his dishonest means of affording his gaudy lifestyle, scolding him for how she didn't raise him to be that and Gina is not to be corrupted like him and disowns him. As Tony gets in his waiting car, Manny comments on Gina's beauty before being severely warned by Tony that she's off limits.
Frank sends Tony and Omar to Bolivia to meet with cocaine production overlord Alejandro Sosa (Paul Shenar). Tony agrees to a deal with Sosa without Frank's approval, and Omar leaves to contact Frank. Sosa discloses that Omar is a police informant and then has Tony witness as a beaten Omar is pushed to his hanging death from a helicopter by "The Skull" (Geno Silva), Sosa's assassin. Tony vouches for the rest of his organization and Frank, and Sosa agrees to the deal, parting with a warning that Tony should never betray him. In Miami, Frank is infuriated by Omar's demise and the unauthorized deal struck by Tony. The relationship between Tony and Frank dissolves, and Tony establishes his own organization and informs Elvira of his intentions toward her.
At the nightclub, Tony is blackmailed by corrupt detective Mel Bernstein (Harris Yulin), who lays out the cost of Tony continuing his business operation in return for police immunity. Tony angers Frank further by openly pursuing Elvira in the club. Tony sees Gina dancing with a drug dealer. He throws the dealer out, and following a heated exchange he slaps Gina before Manny takes her home. Hitmen attempt to assassinate Tony, but he escapes. Suspecting that his former boss sent both Mel and the hitmen, Tony, Manny and Chi-Chi go to Frank's office, where they find him with Mel. When a planned phone call by one of Tony's henchmen sets up Frank's involvement, Manny kills Frank and Tony kills Mel. Tony takes Elvira and seizes Frank's empire.
With Sosa's supplies, Tony builds a multi-million-dollar empire, and he later marries Elvira. However, the operation struggles as Tony and Elvira excessively use cocaine, Tony's money launderer demands more pay, and Manny grows resentful as Tony takes all credit for their success. Eventually, Tony is charged with money laundering and tax evasion after a police sting operation. Sosa offers to use his government connections to keep Tony out of jail if Tony assassinates a Bolivian journalist intending to expose Sosa during a speech to the United Nations. Later, Tony further pushes Manny and Elvira away by blaming his friend for his arrest and accusing his wife of being infertile because of her drug use. After a fight, Elvira leaves Tony.
In New York City, Tony, Chi-Chi and Sosa's henchman Alberto (Mark Margolis) prepare for the assassination. Alberto plants a bomb on the journalist's car, but when he is unexpectedly accompanied by his family, Tony calls off the mission. Alberto insists on continuing, forcing Tony to kill him. Later, Tony learns that Manny and Gina have been missing for several days. Returning home, Tony is contacted by a furious Sosa over the mission's failure. Sosa ends their business relationship and reminds Tony that he should not have betrayed him.
In search of Gina, Tony goes to his mother's house. She gives him an address in Coconut Grove. At the address, Manny opens the door wearing a bathrobe. When Tony also sees Gina in a robe, he kills Manny on an impulse. Gina tells Tony that she and Manny had just gotten married the day before and were planning to surprise him. Tony and his men take Gina to Tony's mansion. Tony declares war on Sosa before burying his face in a large mound of cocaine. Meanwhile, Sosa's men begin assaulting the mansion and killing Tony's men. A drugged Gina accuses Tony of wanting her himself, before shooting him in the leg. One of Sosa's men shoots and kills Gina. Tony kills the man and becomes distraught at the sight of Gina's corpse. Chi-Chi is also killed by Sosa's assassins. In a cocaine-fueled fury, Tony uses a grenade-launcher-equipped rifle to kill several of Sosa's men. Tony is repeatedly shot, but continues to fight until he is shot in the back by The Skull, who crept up behind him. Tony's corpse falls into a fountain below, in front of a statue reading, "The World is Yours."