The subject of the study is the cooperation of S. Efremov with Western Ukrainian periodicals as a page in the history of Ukrainian journalism which covers the relationship of journalists and scientists of Eastern and Western Ukraine at the turn of the XIX-XX centuries. Research methods (biographical, historical, comparative, axiological, statistical, discursive) develop the comprehensive disclosure of the article. As a result of scientific research, the origins of Ukrainocentrism in the personality of S. Efremov were clarified; his person as a public figure, journalist, publisher, literary critic is multifaceted; taking into account the specifics of the memoir genre and with the involvement of the historical context, the turning points in the destiny of the author of memoirs are interpreted, revealing cooperation with Western Ukrainian magazines and newspapers. The publications ‘Zoria’, ‘Narod’, ‘Pravda’, ‘Bukovyna’, ‘Dzvinok’, are secretly got into sub-Russian Ukraine, became for S. Efremov a spiritual basis in understanding the specifics of the national (Ukrainian) mass media, ideas of education in culture of Ukraine at the end of XIX century, its territorial integrity, and state independence. Memoirs of S. Efremov on cooperation with the iconic Galician journals ‘Notes of the Scientific Society after the name Shevchenko’ and ‘Literary-Scientific Bulletin’, testify to an important stage in the formation of the author’s worldview, the expansion of the genre boundaries of his journalism, active development as a literary critic. S. Yefremov collaborated most fruitfully and for a long time with the Literary-Scientific Bulletin, and he was impressed by the democratic position of this publication. The author’s comments reveal a long-running controversy over the publication of a review of the new edition of Kobzar and thematically related discussions around his other literary criticism, in which the talent of the demanding critic was forged. S. Efremov steadfastly defended the main principles of literary criticism: objectivity and freedom of author’s thought. The names of the allies of the Ukrainian idea L. Skochkovskyi, O. Lototskyi, O. Konyskyi, P. Zhytskyi, M. Hrushevskyi in S. Efremov’s memoirs unfold in multifaceted portrait descriptions and function as historical and cultural facts that document the pages of the author’s biography, record his activities in space and time. The results of the study give grounds to characterize S. Efremov as the first professional Ukrainian-speaking journalist.