The novel is presented as a diary written by Zeno (who claims that it is full of lies), published by his doctor. The doctor has left a little note in the beginning, saying he had Zeno write an autobiography to help him in his psychoanalysis. The doctor has published the work as revenge for Zeno discontinuing his visits.

The diary, however, does not follow the chronological order; instead, it is structured in large chapters, each one developing a particular theme (The smoke addiction, My father's death, History of my marriage and so on). Only the last chapter is a real diary, with pages related to single dates in the period of the First World War.