Mendjisky studied at the École des Beaux-Arts in Paris in 1947, and learned the technique of cartooning from Paul Grimaud. He settled in Nice in 1949. He received encouragement from Picasso, Jacques Villon and Dunoyer de Segonzac. He illustrated Jean de Florette (1964) by Marcel Pagnol and published several lithographic works including Port Grimaud accompanied by a text by Henri Troyat. In 1964, he discovered divisionism from the works of Cézanne. He painted many landscapes of the south of France and views of Paris, Chicago, Venice and others places.
Mendjisky's work featured in the major Paris exhibitions: Salon des Peintres Témoins de leur Temps, Salon des Artistes Français, Salon d'Automne, and Salon des Indépendants. His solo exhibitions included: Galerie St-Placide (Paris 1959, 1961); Norwal Gallery (New York 1960); Urban Paris Gallery (Tucson, Arizona 1962, 1964, 1966, 1969, 1972, 1974); Richter Gallery (Philadelphia 1965); Galerie Félix Valotton (Lausanne 1966); Galerie Yves Jaubert (Paris 1973); Musée de St-Paul-de-Vence (1976); Galerie La Licorne (Juan-les-Pins 1980); Richmond Gallery (London 1981, 1985); Galerie de l'Orangerie (St-Paul-de-Vence 1984); and the Galerie Guiot (Paris 1986).