For young Parisian boy Antoine Doinel, life is one difficult situation after another. Surrounded by inconsiderate adults, including his neglectful parents, Antoine spends his days with his best friend, Rene, trying to plan for a better life. When one of their schemes goes awry, Antoine ends up in trouble with the law, leading to even more conflicts with unsympathetic authority figures.

Charlie is a former classical pianist who has changed his name and now plays jazz in a grimy Paris bar. When Charlie's brothers, Richard and Chico, surface and ask for Charlie's help while on the run from gangsters they have scammed, he aids their escape. Soon Charlie and Lena, a waitress at the same bar, face trouble when the gangsters arrive, looking for his brothers.

Now in his thirties, Antoine Doinel is a divorced proofreader in love with a record seller. Colette Tazzi, now a lawyer, buys his first published autobiography, leading them to a chance meeting.