Léon Zack studied painting in private academies at the same time as he studied literature at the University of Moscow. He then spent time at the studios of Ivan Rerberg and Ilya Machkov, who founded the group Jack of Diamonds, which referred to Cézanne, Fauvism and presages of Cubism. In 1913, Zack hesitated between painting and poetry. He published a collection of poems, which he signed under the name Chrysanthe. In 1917, he married Nadia Braudo with whom he had two children: Irène (who became a sculptor) and Florent.

In 1920, Zack and his family left Russia for France via Rome, Florence, and Berlin, where he produced sets and costumes for the Russian romantic ballets directed by Boris Romanov. This troupe was very successful in Berlin and in Paris, where Zack met Michel Larinov and Picasso. His painting was then figurative. In 1930, Zack joined the group of the neo-humanists, which was a movement inspired by the critic Waldermar George, Hosiasson, Christian Bérard, Eugène Berman, and Pavel Tchelitchew. In 1931, he exhibited with this group of artists at the Manteau gallery in Brussels.

In parallel to his artistic career, Léon Zack worked for the Monte-Carlo Ballet and illustrated works by Arthur Rimbaud, Verlaine, Mallarmé, and Baudelaire.

In 1940, he left Paris and took refuge in Arcachon, Villefranche-sur-Mer, and Grenoble. Back in Paris in 1945, Zack exhibited his work at Katia Granoff’s and at the Garets gallery where he showed his abstract works for the first time.

From 1955, Zack worked on religious art. In particular, he produced stained-glass windows for Notre-Dame-des-Pauvres in Issy-Les-Moulineaux and for numerous churches in Paris and in the French provinces.