Notes from the Underground is a self-portrait of a man who calls himself an "antihero." He is never named but writes in first person his views on several issues ranging from free will to man's ability to make intelligent decisions. He then turns to some events in his own life. Fyodor Dostoevsky makes a note at the beginning of the book that the notes and the writer are fictional. He does, however, note that such a person must exist because the current social climate is such that there's no way he couldn't exist. This fictitious author often makes a particular point, then argues as if the reader were submitting objections, then answers. All the while, he insists that he never intends for anyone to read the notes, but writes as if he's writing to an audience. He does say that it's simply a literary device and that it is simply easier for him to write in this fashion.

The writer tells of two incidents in his personal life—encounters with an officer and a prostitute—that were important to him. He meets the officer by chance in a social situation and feels the officer, by pushing past him, had humiliated him. He spends years working on a way to retaliate. He imagines all sorts of encounters and finally borrows enough money to replace the fur collar on his coat. He feels his appearance in the situation he's planning is important. He meets the man on a walkway frequented by many of the day. The author doesn't step out of the officer's way and they bump shoulders. The author feels that he's vindicated and the officer seems never to have known that anything of importance occurred.

The writer spends an evening with friends at a restaurant, though they clearly don't like him and don't want him there. He remains and admits that he does such things out of spite. He then follows them to a brothel, though he has to borrow the money to go there. He is so angry that he says he plans to challenge one of the men to a duel, but they have already disappeared into the various rooms with women. The author has an encounter and then is angry for having allowed it to happen. He rants at her, telling her that she'll grow old and despised quickly and that she should get out of the business. On a whim, he gives her his address and spends the following days worrying that she'll show up. When she does, they have another sexual encounter, though on his part it's revenge because she's seen him in his poverty. She leaves and he considers going after her, but feels he couldn't make her happy because he himself is not happy. He then ends his notes.