Written in the form of journal entries, it follows 30-year-old Antoine Roquentin who, returned from years of travel, settles in the fictional French seaport town of Bouville to finish his research on the life of an 18th-century political figure. But during the winter of 1932 a "sweetish sickness," as he calls nausea, increasingly impinges on almost everything he does or enjoys: his research project, the company of an autodidact who is reading all the books in the local library alphabetically, a physical relationship with a café owner named Françoise, his memories of Anny, an English girl he once loved, even his own hands and the beauty of nature.
Over time, his disgust towards existence forces him into self-hatred and near-insanity. He embodies Sartre's theories of existential angst, and he searches anxiously for meaning in all the things that had filled and fulfilled his life up to that point. But finally Antoine comes to a revelation into the nature of his being when he faces the troublesomely provisional and limited nature of existence itself.
In his resolution at the end of the book he accepts the indifference of the physical world to man's aspirations. He is able to see that realization not only as a regret but also as an opportunity. People are free to make their own meaning: a freedom that is also a responsibility, because without that commitment there will be no meaning.