Johnny Gainesville has spent months searching for his younger brother Joseph "Joey" Gainesville. When the game begins, he is told by his old boss, Clive Otis Click III, that Joey is in Miami. With nothing to lose, Johnny drives down the east coast in search for him. While getting gas, his car his destroyed and he steals the gas station owner's car. He drives into downtown Miami and meets an old man named Roscoe and his younger girlfriend Betty. Roscoe tells Johnny that if he wants to get answers about Joey he will need to "piss off some rivals." Johnny agrees and does a series of jobs that include stealing dead bodies, interfering with drug deals, taking pictures of corrupt police officers, etc. The gas station owner, Albert, from the beginning of the game meets Johnny again and tells him he will need to pay for the car he stole. After a race, Johnny tells Albert that he will be able to give him enough money to buy any car he wants. Roscoe tells Johnny that an inexorable Cuban mob boss named Victor Vega has Joey in his custody. Johnny spies on Vega in the warehouse by the docks and sees him dealing with a Detective named Bolano. He talks about "the little bastard," and Johnny assumes he means his brother. He finds Vega's boat but finds out the "little bastard" is not his brother. Instead he finds millions of dollars in heroin and Roscoe persuades Johnny to give it to him. Betty tells Johnny that a man named Herman Kaye rules the downtown part of Miami and that he will probably have answers for him. Kaye sends Johnny on a number of odd-jobs, most of them being against Monique Jones, whom Herman Kaye had made famous in the music industry, but Jones ended up leaving him to go out on her own. One of the jobs included killing Victor Vega, whom Johnny had arrested after stealing his drugs. While being transferred to a maximum security prison Johnny shoots Vega before he can escape on foot. Johnny leaves Kaye and learns that a pimp known only as Reginald has information on Joey. After Betty scares him in a car ride, he gives up Joey's location: A slaughterhouse in the middle of a cornfield. Johnny and Betty (who have fallen in love, unbeknownst to Roscoe) infiltrate the slaughterhouse and a shootout occurs. They find Joey, being held in a cage but they are soon trapped in a cage themselves. The man who locked them up goes into Betty's cage, intent on raping her, but Betty knocks him out and takes his phone. Johnny tells Betty about a friend in Los Angeles named Luis Custodio (known as L.C. He appeared as a main character in the first game as a prominent mob boss) . Betty asks L.C. to rescue them and a few days later, L.C. arrives and kills the guards surrounding the slaughterhouse. He rescues them and they part ways. Joey, Johnny, Betty, and L.C. meet up outside the swamp where Roscoe has been hiding out for 10 years without the police finding him. Johnny believes that Roscoe had orchestrated the kidnapping of Joey and plans to kill him. Betty informs the men that the police have a flame thrower from Washington with them. Johnny steals it and destroys Roscoe's house with it, but after searching the area, they do not find him. They meet up at the beach in uptown Miami a day later and Joey comes up with a plan to have Roscoe arrested instead of killing him. Johnny causes chaos around the city and leads the police to the swamp where Roscoe is. Roscoe is arrested but how ever long his sentence is is not revealed. Johnny realizes the Roscoe was just a dirty gangster and wasn't behind the kidnapping. He then starts to suspect Herman Kaye, who had him kill Vega, many police officers, and other gangsters. Johnny believes this was a plan to take control of Miami, since none of the jobs had helped him find his brother. Johnny steals Kaye's car from his villa and has Albert put a bomb on it. He parks it in Kaye's driveway and it explodes, but Kaye gets into another car and tries to escape, but Johnny kills him. With everything apparently settled and Miami apparently rid of it's mob, Johnny goes to the airport with Betty, Joey, and L.C. intent on marrying Betty. Before going inside the airport they are attacked by gangsters and are forced to drive back to Kaye's villa, where they are now living. Joey notices that they talk and look like the men that hung out around their hometown. Johnny realizes that the bad guy this whole time was Clive Click. Click sent Johnny to Miami to rid the city of it's mob bosses so Click could take control. Johnny chases Click by car and boat around the city and they finally have a stand down at the airport (the final battle does not reach the epic proportions of the second game's, but it is still very violent and very long) , and Johnny shoots Click multiple times, killing him. He sends L.C and Joey off to L.A where Joey will go to Boarding school and L.C will continue his work. The game ends with Johnny and Betty walking along the beach, talking about their adventure. It is hinted that the fourth game in the Gangstar series will take place in Las Vegas or Los Angeles again.