This article is dedicated to the study of the nature of E. Agafonov’s creative ties with the theater – a topic that has been insufficiently covered in the native art history. The author’s field of view is set in the artist’s early Kharkiv period, marked as the years of 1905–1913. The article focuses on the exceptional role of E. Agafonov in the organization and the artistic practice of the first modernist theater “Blakytne Oko” in Kharkiv (1909–1911). Agafonov belonged to the constellation of masters who was very sensitive to the problem of evolving the artistic speech. He viewed the theater as a convincing platform for promoting and approving of the latest artistic values, discovered by Impressionism and Post-Impressionism. Experiments in easel art (with color, plastic, line, techniques, materials, etc.), largely inspired by the work of D. Burliuk (1906–1908), were directly reflected in Agafonov’s stage practice, namely in numerous designs of the modernist productions based on plays by M. Maeterlinkc, A. Schnitzler, S. Pshybyshevsky and O. Blok. In turn, it was established that theatrical motives were reflected in E. Agafonov’s easel art, as well as in the art of the students of his artistic studio – O. Rybnikov, I. Terentyev, M. Sinyakova, and K. Storozhnichenko. In this regard, a special attention is given to the linocuts by F. Nadezhdin. It was found that the program of “total” design of theatrical space (stage and auditorium), as well as the implementation of production ideas in the cabaret theater “Blakytne Oko” were the result of the master’s fascination with the concepts of artistic synthesis, actualized in the era of Modern. Agafonov moved from dramatization of paintings (of A. Beklin, F. Malyavin, and O. Rodin) to staging experimental show-programs like “The Evening of Autumn”, “Visiting Pierrot” and “In the Middle of Nowhere”, partial reconstruction of which was undertaken for the first time by the author of the article. Agafonov was close to the idea of artistic synthesis, identified by him in F. Malyavin’s paintings, in V. Komissarzhevska’s theatre and I. Duncan’s choreography. The study of E. Agafanov’s theatrical art expands the understanding of the history of formation and development of Ukrainian scenography at the beginning of the twentieth century.