In the Soviet Union of the 1950s, Yevgraf Zhivago is trying to track down the long-lost daughter of his half-brother Yuri and his lover Lara. He finds a young woman who may be their child and tells her the story of Yuri and Lara.

Following the death of his parents, 10-year-old Yuri is sent to live with family friends Mr and Mrs Gromeko and their daughter Tonya in Moscow. His only heirloom is his mother's balalaika.

Eventually Yuri goes on to study medicine in Moscow, planning to go into general practice. He also begins to get some of his poetry published. Lara is a student living with her mother, a dressmaker, and is seeing Pasha, a revolutionary. He is hurt during a demonstration that is violently suppressed by the army. At the same time Komarovsky, a political fixer and her mother's lover, seduces Lara. The next day Tonya returns from Paris and her parents hope that she and Yuri will soon be married. Pasha, badly hurt, goes to see Lara and asks her to hold a gun for him.

Yuri assists when Komarovsky calls for a doctor to take care of Lara's mother, who attempted suicide when she heard of his affair with her daughter. Days later, Pasha and Lara tell Komarovsky that they plan to marry. He is against the idea and in anger he insists she have sex with him, after which he leaves. She eventually tracks him down to a Christmas party where Tonya and Yuri's engagement is announced. Using Pasha's gun, she shoots and wounds Komarovsky. While Yuri treats the wound, Pasha comes to take her away. She tells him of the affair and he eventually forgives her and the two marry.

World War One breaks out and Pasha enlists. The heavy casualties prompt the Bolshevik revolution. Lara and Yuri meet while she is looking for him. The two spend six months together far away from home treating the sick and wounded and, although they become very close, they remain faithful to their respective spouses. Eventually, when the hospital closes, Yuri returns to Tonya and his son in Moscow. He finds that the government has turned his home into a communal dwelling for dozens of people. There are many privations in the city, with food and fuel running short. They are visited by Yevgraf who tells them that Yuri's liberal humanism, and his poetry, are falling foul of the authorities, finally convincing him to leave the city for the country. The family heads for their old family home in the Urals. During a break in the long journey, the men of Commander Strelnikov, an almost legendary leader, pick up Yuri. He recognises Strelnikov as Pasha, and discovers that Lara is living near his final destination.

The family moves into a small part of what used to be their estate and life begins anew as Tonya falls pregnant with their second child. Yuri and Lara meet by chance the following spring and begin an affair. Yuri begins a double life, trying to be true to both his loves. While returning from Lara's home, he is kidnapped by Red partisans who need a doctor. He eventually spends two years with them before he manages to escape home. He discovers that Tonya and the children have moved to Paris to avoid deportation and that they have left his balalaika with Lara for safekeeping.

Yuri and Lara move to his old dacha, which is now completely frozen over. While there, he writes a series of poems about Lara and tries to make up for all his lost time with her. Komarovsky, now the Minister of Justice, finds them and tells them that Lara has been under observation. Strelnikov was captured only five miles from there and he then killed himself. Komarovsky convinces them to leave by a special train heading for Mongolia, but Yuri, after giving Lara his balalaika, fails to join them. Lara, pregnant with Yuri's child, knows that he loves Russia too much to leave it. She and Yuri will never meet again.

Yevgraf tells of how he tried without success to re-unite Lara and her child after they were separated some years later. He also managed to help Yuri when he found him living in poverty in Moscow. Some time later, while riding a tram, Yuri sees Lara walking down the street, but she doesn't see him. As he tries to reach her, the strain is too much for his weak heart and he dies. Lara herself later disappears in a labour camp.

Concluding his tale, Yevgraf becomes convinced that the girl must be the child of Yuri and Lara when he discovers that she has a natural ability to play the balalaika.