It received contributions from Louis Aragon, François Mauriac, Claude Morgan, Édith Thomas, Georges Limbour, Raymond Queneau and Jean Lescure.

After the Liberation and until 1972, Les Lettres Françaises, managed by Aragon, was financially supported by Soviet government[citation needed] and the French Communist Party.

The newspaper frequently served as a reflector of Soviet state propaganda, in late 40's engaging in defense of pseudo-scientific Lysenkoism.

Pierre Daix wrote "French scientists recognize superiority of Soviet science" article which was then reprinted in Eastern Bloc newspaper, intending to create an impression that Lysenkoism was already accepted by the whole progressive world.

During this interval, it supported De-Stalinization and liberalization efforts, looked with sympathy toward the Prague Spring, and, in August 1968, criticized the Soviet invasion of Czechoslovakia.