During the 1870s in Moscow, Prince Stepan Arkadyevitch Oblonsky is in trouble for having an affair with his children's former governess. Stepan is not repentant, but he is sorry that he did not do a better job of hiding his adultery from his wife. Stepan receives a telegram saying that his sister, Anna Arkadyevna Karenina, will visit him the following day. Stepan's servants hope that Anna will be able to reconcile Stepan and his wife, Darya Alexandrovna, "Dolly."
Dolly loves her husband but can't bring herself to forgive him for his infidelity. Dolly locks herself in her room and refuses to tend her children or take care of other household matters. Stepan leaves the house to go to his government job. At work, Stepan's childhood friend Konstantin Dmitrievitch Levin arrives for a visit. Levin lives in the country and does not understand how Stepan can enjoy city life. Levin has come to ask how Kitty Shcherbatsky, Dolly's sister and Stepan's sister-in-law, is doing. Levin is in love with Kitty and plans to propose marriage to her.
Levin finds Kitty ice-skating with her family at the Zoological Gardens. Kitty invites Levin to skate with her, and she enjoys his company until she senses that his feelings for her have grown romantic. Kitty distances herself from Levin, who is hurt by the idea that the woman he loves will likely reject his proposal. Levin shares a meal with Stepan, who encourages him to propose to Kitty but also warns him that Kitty has another suitor, Count Alexey Kirillovitch Vronsky. When Levin calls on Kitty and asks her to marry him, she politely refuses him because she likes Levin but prefers Vronsky.
Levin meets Vronsky while both men are visiting the Shcherbatskys. Vronsky seems very interested in Kitty, but he is not considering marriage.
Vronsky goes to the train station to welcome his mother to Moscow. As he is getting off the train, he notices a high society woman. Vronsky's mother introduces him to this woman, Anna Karenina. Anna is a young wife and mother who has come to Moscow to visit her brother Stepan Oblonsky, who is Vronsky's friend. At the station, Vronsky and Oblonsky see the dead body of a guard who fell into the path of the train. Bystanders imply that the guard threw himself in front of the train on purpose. Vronsky sends a servant to give money to the guard's widow when he hears that the man was the sole provider for his family.
Anna goes to see Stepan's wife, Dolly. Anna assures Dolly that Stepan has only been physically unfaithful and that his heart is still loyal to Dolly and his children. Anna meets and befriends Kitty when the younger woman visits the Oblonskys' house. Dolly and Stepan reconcile, and Anna is pleased to be the cause of their reunion.
The next week, Anna, Kitty and Vronsky all attend a high society ball. Vronsky dances with Kitty, but Kitty is disappointed that he chooses to save the last dance of the evening for Anna. Kitty notices that Vronsky and Anna already look at each other with complete adoration, and she knows that her hopes for marrying Vronsky are over.
Levin returns to his country home. Anna leaves Moscow to return to her home in St. Petersburg. Vronsky meets Anna at the train platform in St. Petersburg, and she knows he has followed her because he has fallen in love with her. Anna is delighted by Vronsky's attention, but she tells him to leave her alone. Anna soon meets with her husband, Karenin, and Vronsky rushes to introduce himself. Karenin agrees to let Vronsky come visit their home at a later date.
In Moscow, Kitty's health deteriorates from the emotional trauma of refusing Levin and being abandoned by Vronsky. Kitty's family decides to send her to Europe for a foreign tour to lighten her spirits.
In St. Petersburg, Anna stops spending time with her religious friend Countess Lydia and begins a friendship with the fun and frivolous Betsy Tverskaya, who is Vronsky's cousin. Vronsky frequently meets with Anna at society gatherings, and although she does not encourage his courtship, she is always delighted by his attention. Anna finally tells Vronsky to go back to Moscow and reunite with Kitty, but he makes another declaration of his love for Anna. Anna's husband, Karenin, arrives at the party where Anna and Vronsky are talking, but he joins another conversation and does not disturb their private talk. Everyone in the room seems to notice their flirtation. Karenin grows suspicious of Anna's relationship with Vronsky only because other people are suspicious of them. He advises her to be more cautious in her behavior toward Vronsky in the future.
One year later, the story skips to a time shortly after Anna and Vronsky have committed adultery for the first time. Anna cries and feels ashamed, while Vronsky tries to console her.
Vronsky gains the respect of many young men who think his conquest of Anna is very brave. The young women around Anna treat her with disdain for her degraded morals.
In the countryside, Levin spends his time tending to his farm and trying to recover from Kitty's rejection. Stepan Oblonsky comes to visit Levin, and tells him that Kitty is very sick and has been sent to Europe to recover from her illness.
Vronsky continues his affair with Anna, and also pursues his passion of horseracing. He buys a mare named Frou-Frou and enters a steeplechase for military officers. Before the race, Vronsky goes to visit Anna, who tells him that she is pregnant. Vronsky tells Anna that she must leave her husband so the two of them can move away. He leaves for the steeplechase, but during the race he accidentally breaks his mare Frou-Frou's back by shifting in his saddle as the horse is jumping. After Vronsky is injured in the race, Anna tells her husband, Karenin, that she loves Vronsky. Karenin tells her to maintain the outward appearance of propriety until he can decide what to do about their situation.
Kitty Shcherbatsky and her parents are staying at a spa in Germany to help improve Kitty's fragile health. Kitty becomes friends with Madame Stahl, a pious woman confined to a wheelchair, and Varenka, Madame Stahl's young ward. Kitty tries to imitate Varenka's selfless habit of thinking only of others' needs. Kitty's father, Prince Shcherbatsky, is unimpressed with Madame Stahl's religious fervor. He tells Kitty that Madame Stahl is not truly an invalid; she simply stays hidden in her wheelchair because she has short, unattractive legs. Kitty is very disillusioned with Madame Stahl, whose apparent virtues she had once admired.
Levin continues to work hard on his estate in the countryside. He receives a letter from Stepan Oblonsky, asking him to go and visit Dolly, who has moved to a rustic house nearby and is having a difficult time managing a country life with her six children. Dolly is living in the country to lower the Oblonsky family's expenses while Stepan is enjoying a rich life in St. Petersburg. Levin enjoys visiting Dolly and the children. Dolly tells Levin that her sister Kitty will be coming to stay with her in the summer, and Levin admits that he once proposed to Kitty and was refused. Dolly encourages Levin not to give up on the idea of marrying Kitty, but Levin says that he will not think of Kitty romantically again.
Anna's husband, Karenin, decides to punish her infidelity by not granting her the divorce she desires. Karenin does not love his wife and is no longer jealous over her adultery, but he does want to see her punished for insulting his honor. Anna is angry that Karenin will not divorce her. She wants to leave him and take their son, Seryozha, with her, but she decides against such a drastic move. Anna believes that she will never have enough resolve to leave her husband and her place in society in order to live with Vronsky as his mistress.
Vronsky finds himself in debt because his mother does not approve of the way he has been neglecting his military career in order to spend most of his time with Anna. He is now unsure whether Anna should leave her husband and come to live with him. Vronsky feels that he needs more money in order to support Anna, and he thinks he may also need to retire from the military if he and Anna set up housekeeping together. Anna wants to be with Vronsky but does not want to leave Seryozha with Karenin. Karenin only demands the outward appearance of virtue from Anna and does not mind if she keeps seeing Vronsky, so long as Vronsky never visits their home.
Anna continues living with Karenin, but the two of them rarely speak. Anna grows suspicious of Vronsky's activities and fears that he is seeing other women. Vronsky knows he can never leave Anna, but he is no longer happy with her. Anna is due to give birth to Vronsky's child soon, and she tells Vronsky that she expects to die in childbirth because she has had a bad dream foretelling her death.
Karenin sees Vronsky visiting his home, and this sight convinces Karenin to divorce Anna. After meeting with a lawyer, Karenin learns that it may be difficult to gain a divorce from Anna without definitive proof of her infidelity. Karenin still wants a divorce, but is unsure of how to proceed.
Karenin visits Moscow and accidentally meets with Stepan and Dolly Oblonsky. Stepan throws a dinner party and invites Karenin, as well as Kitty and Levin, who meet each other formally for the first time since Kitty refused Levin's marriage proposal. Kitty and Levin sit next to each other at dinner and share an enjoyable conversation, which proves that they both have romantic feelings for each other. Levin proposes to Kitty again, and she accepts. Kitty's parents approve of the match, and arrangements are made for the wedding.
Karenin receives a letter from Anna, who begs him to forgive her. Anna is having a difficult labor with her second child, and she believes she is dying. Karenin returns to St. Petersburg to find Anna in a feverish state after giving birth to her daughter. Karenin forgives Vronsky for his affair with Anna, and Vronsky feels ashamed. Vronsky's humiliation is so extreme, he tries to commit suicide by shooting himself in the chest. However, his attempt is unsuccessful, and his sister-in-law nurses him back to health.
Anna makes a surprise recovery from her illness. Karenin realizes that he still loves her, and he forgives and pities her. Karenin also begins to love baby Annie, his wife's illegitimate child. Anna is disgusted with Karenin and still hates him, despite his kindness. Anna decides not to get a divorce from Karenin, but she no longer wants to live with him. Vronsky retires from the military, and he, Anna and Annie leave St. Petersburg to travel abroad.
Preparations for Levin and Kitty's wedding continue. Levin feels unworthy of Kitty's love and begins to question whether Kitty truly loves him or if she merely wants to be married. Kitty reassures him of her affection, and the wedding proceeds. Kitty and Levin move immediately to Levin's home in the countryside.
Anna and Vronsky travel in Italy and settle down in a rented palazzo house. Anna is very happy with her life in Italy, but Vronsky is less content. Now that all of Vronsky's desires have been fulfilled, he misses having an unattainable desire. The two of them become bored of their life in Italy and resolve to return to St. Petersburg.
Levin and Kitty have been married for three months, and although they have many small fights over domestic matters, both of them are happy. Levin hears that his brother Nikolai is dying, and he and Kitty leave for Moscow to visit Nikolai. Kitty and Levin look after Nikolai until he dies. Kitty learns that she is pregnant.
Karenin has been living alone in St. Petersburg with his son, Seryozha. Without Anna, he lives a sad and humiliated existence. Anna and Vronsky return to St. Petersburg, but they begin to realize that no high society people will speak to Anna or associate with her. One night, Anna goes out to see the opera and is insulted by one of her old acquaintances. Anna and Vronsky leave for the countryside.
Dolly Oblonsky and her children stay with Kitty and Levin for the summer. Levin's brother Sergei and Kitty's friend Varenka also stay with them for a while. Sergei contemplates proposing to Varenka but decides against it. Dolly goes to visit Anna, and as she travels, she thinks about her own unhappy life and wonders whether Anna might have chosen the best path in life by leaving her husband.
Anna is thrilled to receive Dolly, and she confesses that she is again completely happy in her life with Vronsky. Vronsky and Anna are living in great luxury, and Vronsky is undertaking some charity projects and helping the local peasants by building a hospital for them. Vronsky is worried that his daughter, Annie, is technically a Karenina since Anna has not obtained a divorce from Karenin. Dolly tries to convince Anna to ask Karenin for the divorce so that she can marry Vronsky. After a long period of deliberation, Anna does write to Karenin for the divorce, and she and Vronsky move to Moscow.
Kitty and Levin move to Moscow for Kitty's confinement so that she can be near the best doctors. Kitty briefly meets with Vronsky, and she is pleased by the fact that she is no longer in love with him and can now speak to him calmly. Levin and Vronsky become friends. Stepan Oblonsky invites Levin to come with him to meet Anna, and Levin is charmed by Anna's wit and beauty. Anna wonders why Vronsky is no longer as charmed by her as new acquaintances are, and she fights with Vronsky over his freedom to move about in society while she is bound to him and can rarely leave their home. Kitty gives birth to a healthy son, Dmitri.
Karenin changes his mind about granting Anna a divorce. Anna and Vronsky's relationship grows more and more strained. Anna is constantly jealous of Vronsky although he gives no indication that he is being unfaithful to her, and Vronsky is constantly exasperated with Anna. After one particularly bitter argument, Anna begins to imagine that death will solve all her problems. By dying, Anna will no longer feel the shame of her fallen state, the pain of being separated from her son, Seryozha, or the anxiety of wondering whether Vronsky still loves her.
Vronsky briefly leaves Anna to go visit his mother, and Anna goes to meet him at the train station. At the train station, Anna's thoughts of suicide become all consuming, and she jumps in front of an oncoming train. She briefly regrets her decision, but it is too late to avoid the train's impact, and Anna is killed.
A few months after Anna's death, Vronsky volunteers in the Russian army, which is mobilizing to help liberate the Slavs in Serbia. Vronsky's mother tells Levin's brother Sergei that Vronsky wouldn't speak to anyone for six weeks after Anna's death and that his family kept him on a suicide watch for that period of time. Karenin adopts Annie.
Sergei goes to visit Kitty and Levin in the country. Kitty is glad to see him because she thinks his visit might improve Levin's mood. Levin has been contemplating the meaning of life and reading philosophical books, and Kitty is worried about his gloomy attitude. Levin has a conversion experience and becomes a Christian. A storm strikes the countryside, and Levin worries about Kitty, who has taken their infant son, Dmitri, out into the woods. He finds his wife and baby unharmed by the storm, and Kitty is grateful that Levin finally seems to have some genuine love for his son. Levin looks forward to the future, knowing that he is not perfect but that he has found meaning in his life.