This paper presents Eugenia Sokolnicka, a Polish analyst who belongs to the first generation of psychoanalysts. The article provides an overview of Sokolnicka's clinical and theoretical work, describes her contribution to psychoanalysis and portrays her as a brilliant clinician and a precursor of child analysis. As a student of CG. Jung, S. Freud and S. Ferenczi, she played a significant role in the development and promotion of Freud's method in literary and medical circles. Sokolnicka unsuccessfully attempted to establish the Polish Psychoanalytical Society and participated in the process of forming psychoanalytical institutions in France. The analysis of her papers presents her contribution to various fields of theory and techniques of psychoanalysis. Furthermore, the research on letters written between S. Freud, S. Ferenczi, K. Abraham and O. Rank provides insight into Sokolnicka's life and personality.