Stematsky was born in 1908 in Odessa. He joined the Massad group in Tel Aviv. In 1929, he went to Paris to study at Académie de la Grande Chaumière and Académie Colarossi. He was one of the founders of the New Horizons group. He held his first solo exhibition at the Tel Aviv Museum of Art at the age of 31. In the constellation of Israel art, Stematsky and Yehezkiel Streichman stand out as a pair. Although each developed his own distinct, individual style, there are many points of affinity between them: a common background as students of Bezalel in the 1920s, a response to the influences of the Jewish School of Paris in the 1930s, and of the "modern" (late cubist) art in the 1940s and fifties, when they were also leading teachers in Tel Aviv.