Léon Bellefleur has always shown a great interest in art.
It was in 1946 that his first exhibition took place, his works having been presented with the drawings of the children to whom he taught. A year later, he published "Plaidoyer pour l'Enfant". In 1951, he won first prize for modern painting at the Salon du Printemps of the Montreal Museum of Fine Arts.
In 1948, in reaction to the Automatists, whose principles he sometimes considered too radical, he became one of the signatories of the manifesto "Prisme d'Yeux", written by the painter Jacques De Tonnancour, which called for total freedom of expression in art.
Bellefleur works on a pictorial ordering of chance and the subconscious, the outcome of which is presented as a lyrical abstraction. In 1985, he received the Louis-Philippe Hébert Prize from the Société Saint-Jean-Baptiste, awarded to great Quebec painters, including Pellan and DeTonnancour who were his close friends.