The original French title of the film comes from a line in Charles Trenet's song "Que reste-t-il de nos amours?" which is also used as the film's signature tune.
The New Wave was already ten years old, but this was the first time a film by one of its core members received the prestigious yearly critics award, the Prix Louis Delluc.
The book that Doinel reads in the lobby hotel scene is "La Sirène du MIssissipi", the film François Truffaut would direct after this one.
The book that Doinel reads in the first scene is Le Lys dans la vallée (The Lily in the Valley) by Honoré de Balzac.