The article elucidates the outstanding contribution to the study of Russian literature and Croatian-Russian literary relations of the famous Croatian scholar Alexander Flaker, one of the most significant representatives of Zagreb school of literary style, the founder of Zagreb school of Russian Literature study. Flaker’s scientific heritage is enormous, he owns over 700 publications, including works concerning the influence of Turgenev’s work on the development of Croatian prose in the second half of the 19th century, on the connections of Russian and Croatian literature of the 20th century (the works by A. Che­khov, S. Yesenin, M. Sholokhov and others). The results of the long standing work are summarized in the monograph “Russian Avant-Garde” (1984).