He published a detective novel in 1986, Pour cent millions at Éditions Liana Levi [fr] (prix Michel-Lebrun), then had some theatre plays performed,[1] including Grand, beau, fort, avec des yeux noirs brûlants..., in 2008 at festival d'Avignon.

His publisher Albin Michel nonetheless presented Le Club des incorrigibles optimistes issued in 2009 as the first novel of a 59-year-old unknown.

[3] In this almost 800-page book, Jean-Michel Guenassia had the ambition to write both the "novel of a generation" by carefully reconstructing the 1960s (the Cold War), the Algerian question, the appearance of rock and roll etc.)

The title is justified by the decisive location of the novel, the back room of a Parisian bistro frequented by Joseph Kessel and Jean-Paul Sartre, where there are men who fled Communism of Eastern countries (Igor, former Russian doctor threatened by the Stalinist purges, Pavel former Czech diplomat ...) but who are all "incorrigible optimists".

It was awarded the Prix Goncourt des lycéens on 9 November 2009[5] and the 2010 readers Prize of Notre Temps.