Set in late 19th-century Kristiania (now Oslo), the novel recounts the adventures of a starving young man whose sense of reality is giving way to a delusionary existence on the darker side of a modern metropolis.

In many ways, the protagonist of the novel displays traits reminiscent of Raskolnikov in Crime and Punishment; the author, Fyodor Dostoevsky, being one of Hamsun's main influences.

Hunger encompasses two of Hamsun's literary and ideological leitmotifs: The novel's first-person protagonist, an unnamed vagrant with intellectual leanings, probably in his late twenties, wanders the streets of Norway's capital, Kristiania (Oslo), in pursuit of nourishment.

Over four episodes he meets a number of more or less mysterious persons, the most notable being Ylajali, a young woman with whom he engages in a mild degree of physical intimacy.

He exhibits a self-created code of chivalry, giving money and clothes to needy children and vagrants, not eating food given to him, and turning himself in for stealing.

Essentially self-destructive, he thus falls into traps of his own making, and with a lack of food, warmth and basic comfort, his body turns slowly to ruin.