The academy-trained painter Đuro Tiljak attended the College of Art in Zagreb from 1914 to 1915 studying under Oton Iveković and Menci Klement Crnčić. At the beginning of 1919, he left for Moscow and enrolled at the Art Academy in the class of Wassily Kandinsky. Tiljak returned to Zagreb in the same year and ultimately graduated from the Art Academy in 1923 under professor Ljubo Babić. From 1928 to 1929, he continued his studies at the Ecole du Louvre in Paris. In 1930, Tiljak became a member of the group „Earth“. In 1942 he joined the resistance's National Liberation Movement. Later, in 1944, Tiljak participated in an art colony in Cozzano with Marijan Detoni and Oton Postružnik. Tiljak became full-time professor at the Academy of Fine Arts in Zagreb in 1945.

At the beginning he mostly painted landscapes around Zagreb, figural compositions, still nature and animals. During that time he was influenced by the works of post-impressionism. During 1930's he painted in the spirit of magical realism. His rational construction of firm volumes did not have any impact on his cromatic sensitivity.