Amir recalls an event that happened twenty-six years before, when he was still a boy in Afghanistan, and says that that made him who he is. Before the event, he lives in a nice home in Kabul, Afghanistan, with Baba, his father. They have two servants, Ali and his son, Hassan, who are Hazaras, an ethnic minority. Baba’s close friend, Rahim Khan, is also around often. When Afghanistan’s king is overthrown, things begin to change. One day, Amir and Hassan are playing when they run into three boys, Assef, Wali, and Kamal. Assef threatens to beat up Amir for hanging around with a Hazara, but Hassan uses his slingshot to stop Assef.
The story skips to winter, when the kite-fighting tournament occurs. Boys cover their kite strings in glass and battle to see who can sever the string of the opposing kite. When a kite loses, boys chase and retrieve it, called kite running. When Amir wins the tournament, Hassan sets off to run the losing kite. Amir looks for him and finds Hassan trapped at the end of an alley, pinned with his pants down. Wali and Kamal hold him, and Assef rapes him. Amir runs away, and when Hassan appears with the kite, Amir pretends he doesn’t know what happened. Afterward, Amir and Hassan drift apart. Amir, who is racked by guilt, decides either he or Hassan must leave. He stuffs money and a watch under Hassan’s pillow and tells Baba that Hassan stole it. When Baba confronts them, Hassan admits to it, though he didn’t do it. Shortly after, Ali and Hassan move away.
The story jumps to March 1981. Baba and Amir are in the back of a truck as they escape from Kabul, which was invaded by the Soviets and has become a war-zone. After a hellish journey, they make it to Pakistan. Two years later, Baba and Amir live in Fremont, California. While Baba works at a gas station, Amir finishes high school and goes to college. Baba and Amir sell things at a flea market on Sundays, and Baba sees an old friend, General Taheri. Amir notices General Taheri’s daughter, Soraya. When Amir finally speaks to her, General Taheri catches him and tells him there is a proper way to do things. Not long after, Baba is diagnosed with lung cancer. Amir asks Baba if he will get General Taheri’s consent for Amir to marry Soraya. General Taheri accepts the proposal. They hold the wedding quickly because of Baba’s health, and Baba dies a month later. Amir and Soraya try unsuccessfully to have a baby while Amir works on his writing career.
Amir gets a call from Rahim Khan. Rahim Khan is sick and wants Amir to see him in Pakistan. Amir meets him a week later, and Rahim Khan tells Amir about the devastation in Kabul. He says things only got worse after the Soviets were forced out. Now the Taliban rule by violence. He has a favor to ask of Amir, but first he needs to tell him about Hassan. When Baba and Amir left Afghanistan, Rahim Khan watched their house. Out of loneliness and because he was getting older, he decided to find Hassan. He convinced Hassan and Hassan’s wife, Farzana, to come back to Kabul with him. Farzana and Hassan eventually had a little boy, Sohrab. A few years later Rahim Khan went to Pakistan for medical treatment, but he received a call from a neighbor in Kabul. The Taliban went to Baba’s house and shot Hassan and Farzana and sent Sohrab to an orphanage.
Rahim Khan wants Amir to go to Kabul and bring Sohrab back to Pakistan, where a couple lives that will take care of him. He tells Amir that Baba was Hassan’s father, and Amir agrees to do it. In Afghanistan, Amir finds the orphanage where Sohrab is supposed to be, but he is not there. The orphanage director says a Taliban official took Sohrab a month earlier. If Amir wants to find the official, he will be at the soccer stadium during the game the next day. Amir goes to the game, and at half-time, the Taliban put a man and a woman in holes in the ground and the official Amir is looking for stones them to death. Through one of the Taliban guards, Amir sets up a meeting with the official.
When they meet, Amir tells the official he is looking for a boy, Sohrab, and the official tells the guards to bring the boy in. Sohrab is wearing a blue silk outfit and mascara, making him appear more feminine and suggesting that the men sexually abuse him. The official says something Amir recognizes, and suddenly Amir realizes the official is Assef. Assef says he wants to settle some unfinished business. He beats Amir with brass knuckles, breaking Amir’s ribs and splitting his lip. Sohrab threatens Assef with his slingshot, and when Assef lunges at him, Sohrab shoots him in the eye, allowing Amir and Sohrab to escape. As Amir recovers in the hospital, he finds out there never was a couple that could care for Sohrab. Amir asks Sohrab to live with him in the U.S., and Sohrab accepts.
The adoption officials tell Amir that adopting Sohrab will be impossible since he can’t prove Sohrab’s parents are dead, and Amir tells Sohrab he may have to go back to an orphanage. Amir and Soraya figure out a way to get Sohrab to the U.S., but before they can tell Sohrab, Sohrab tries to kill himself. He lives, but he stops speaking entirely. Even after they bring Sohrab to California, Sohrab remains withdrawn. One day, they go to a park with other Afghans. People are flying kites. Amir buys one and gets Sohrab to fly it with him. They spot another kite and battle it. Using one of Hassan’s favorite tricks, they win. Sohrab smiles, and as the losing kite flies loose, Amir sets off to run it for Sohrab.