The Ukrainian philologist, philosopher, psychologist and didactic V. V. Repkin (1927) is the third most important figure in the Elkonin-Davydov system, however, his work is virtually unknown in the West, especially in Brazil. This educator and scientist made important contributions to the system and, in general, to the developmental didactic of activity in fields as diverse as: theory of study activity, Russian language teaching methodology, teacher training, transition between different levels of education, system diagnosis, creation and consolidation of groups and research centers, as well as the foundation of the International Association of Developmental Education. This article specifically approaches Repkin’s theoretical and methodological contributions in three specific fields of knowledge: 1) activity (content, objectives, tasks and structure); 2) transition from the primary to the secondary level of studies (the new contents of the learning activity, new methods and teacher training) and; 3) developmental teaching of language and the problem of orthographic alphabetization (the phonetic principle, the formation of the phoneme concept, and orthographic writing). One has concluded that most of the work written by V.V.Repkin remains in the Russian and Ukrainian language, which makes it difficult to know its contributions, mainly in the field of the psychological and didactics theory of the Study Activity and the specific didactics of the Russian language. V.V.Repkin, besides criticizing the traditional school because it wrongly tries to prepare for a whole life, formulated a new proposal for the basis of the idea of developmental teaching, whose fundamental aim is to form in the subject the Study Activity that leads to his own transformation via theoretical thought formation (scientific concepts, ways of action and principles of action). Within the study activity theory, V.V.Repkin has contributed specifically in relation to, on one side, the study of developing cognitive interests, its differences to the needs, as well as the attachment existing between them; on the other side, going deeply into the principles of action as a component of the theoretical thought. About the transition process from a level to another, V.V.Repkin contributed pointing to the main challenges inherent to such question, mainly, the methods and contents belonging to the next level and the kind of suitable formation that was necessary for teachers. One has also considered that for the teaching of the Russian language the same hypothesis elaborated for primary teaching could be used, at the same time defended a specific way of Study Activity that had permitted the intimate and personal communication of the adolescents, as well as the learning of regulations of social and organizational work. Based on these and other contributions, it is possible to measure the magnitude of the theoretical and didactics work of V.V.Repkin, which still may be of great utility in the current Brazilian context, taking into consideration the different realities for the improvement of teaching and education.