During an interval in a trial, several legal professionals converse in a private room. Peter Ivánovich, the title character's closest friend, reads in the obituaries that Iván Ilych has died. Iván Ilych had been terminally ill for some time. He was the colleague of the men present. The men immediately think, each to himself, of how Iván Ilych's death may result in promotion for them all. Each man thinks gratefully that Iván Ilych is dead and not he. They also think of how they will be forced to go through all the tedious business of paying respects and visiting the family.
Later that day Peter Ivánovich goes to Iván Ilych's house.
Iván Ilych's face seems somehow handsomer in death than in life, and is marked by some kind of expression of satisfaction. The face also seems to bear some kind of warning to the living.
Before service, Praskóvya Fëdorovna (Iván Ilych's wife) and Peter Ivánovich have a talk, where she describes her husband's horrible sufferings: the last three days before his death, he screamed continuously. She then asks Peter Ivánovich advice about pensions and governments grants.
On his way out, Peter Ivánovich sees Iván Ilych's daughter and her fiancé, as well as Iván Ilych's young son. He attends the services. On the way out he comments to Gerásim, Iván Ilych's sick nurse, about the sadness of the occasion, but the peasant says simply that it's God's will and the fate of all men.
Peter Ivánovich still has plenty of time that evening to play bridge.
With the preface-aftermath finished, Tolstoy returns to the beginning, moving back in time nearly three decades. "Iván Ilych's life had been most simple and most ordinary and therefore most terrible." His death at age 45 follows a nondescript career as a member of the court of justice.
Beginning in the title character's youth: Iván Ilych is the middle son of a bureaucrat. He attends the School of Law. He is unquestioningly admiring of those in high station, and seeks to imitate them however he can. After law school he qualifies for a position in the civil service.
His work takes him to the provinces as an official serving the governor. A second move makes him examining magistrate in his new town, where he makes friends with the local society and takes up cardplaying. He marries Praskóvya Fëdorovna, the best girl in his set. His wife becomes difficult starting with the first pregnancy. Iván Ilych deals with her by devoting himself more fully to work. They settle into an aloof marriage. Iván Ilych continues to cherish propriety, decorous living, and pleasantness, through moves and various promotions and the births and deaths of several children. Years pass: at last, his eldest daughter is sixteen and his one surviving son is a schoolboy.
After a career setback, Iván Ilych fights for a post with high salary, and ends up with a job in Petersburg. He throws himself into decorating. One day, when draping hangings, he slips and bumps his side. The pain goes away before long.
The family settles into their new life, making friends with the right sort of people, and Iván Ilych does his job adequately. He lives life as he believes life should be lived: "easily, pleasantly, and decorously" (133).
A pain in Iván Ilych's left side grows, connected to the fall he had while hanging drapes, and he now has a chronic unpleasant taste in his mouth. He becomes more irritable, and begins seeing doctors, who diagnose his illness as an appendix problem. Gradually, his illness worsens, he loses pleasure in playing cards, and he grows increasingly alienated from those around him. He ends up moving into a separate room, where his mobility decreases.
In the third month of his illness, he no longer can control his bodily functions, and a peasant lad named Gerásim is appointed to take care of him. Gerásim is pleasant, and Iván Ilych likes being around him, even though most people nowadays disgust him. Iván Ilych becomes increasingly aware of the hypocrisy and lack of compassion in the people around him, including doctors and his own family. His hatred for these people, especially his wife, increases as his death approaches. Only Gerásim and Iván Ilych's son seem to really care for him.
The routine of Iván Ilych's life becomes increasingly difficult. He is forced to take opium to fight the pain, and his mental anguish becomes more terrible as he fights the realization that he has wasted his life. He has dreams of a black sack with no bottom, into which he is endlessly being pushed.
When the end seems near, at his wife's behest, Iván Ilych takes communion.
The last three days of his life, Iván Ilych screams in agony. But on the third day, he has a revelation. As his son touches his hand, Iván Ilych finally recognizes that the way he has lived his life has been hypocritical and empty. He falls through the bottom of his dream's black sack and sees a great light. The light is comforting. He accepts that compassion is the key to correct living, and tries to ask his wife for forgiveness. He feels not hatred for others, but pity. He retreats into his inner world at the end. Though he seems to be in agony, internally Iván Ilych is at peace as he dies.