While living in Paris's Saint-Germain-des-Près in 1951, Le Maréchal wrote poems and drew ghost houses in dead cities. He made his first visionary paintings, including "La mécanique mange les maisons", in Morocco, where he lived for a year.
In 1954 he rented a room in London and painted "Angoisse-palace" and "L'Amour au bordel populaire". During his stay in London in 1955-1956, he also discovered engraving.
His first exhibition was organized in London, United Kingdom in 1955. In 1983 Le Maréchal had an exhibition at Galerie Michèle Broutta, titled "Catalog of the Engraved Works 1956-1986". His last personal exhibition was at the Galerie 1900-2000 (Marcel Fleiss) in 1993.
Jacques Le Maréchal died in April 2016.
He was considered by some as the leader of the informal movement called "The Visionaries".