The article is devoted to the transformation of the education system in the western Ukrainian lands after the fall of Polish statehood in 1939 and their annexation to Soviet Ukraine. On the example of one of the six new administrative-territorial entities – the Rivne region, the Sovietization of education: the creation of a network of secondary and vocational schools, Ukrainization, the elimination of illiteracy, and the development of communist ideology was studied.Unification of the educational process in the western regions of Ukraine following the current in the USSR and the quantitative growth of schools required the training of teachers with established Marxist-Leninist worldviews. To provide educational institutions with skilled workers, the Soviet leadership has created three pedagogical schools in the Rivne region – in Ostroh, Dubrovytsia, Derman; the first higher educational institution – Rovno State Teachers’ Institute; Rovno Institute for Teacher Training for retraining local staff, as well as has organized the arrival of teachers from the central and eastern regions of Soviet Ukraine.The atmosphere of Soviet everyday life, the working conditions of teachers during the years of the totalitarian regime are highlighted, the specific examples of punitive and repressive actions against teachers and students are shown. Educational work was an important component of the educational process in educational institutions, which was based on political and ideological principles, the core of which was the formation of communist beliefs, internationalism, atheism, and militarism in students.During the first period of Sovietization, education was reorganized, the number of schools and students in the cities and villages of the Rivne region increased. The structure of the general educational institutions of Rivne, which took into account the national composition of student youth, was analyzed, and therefore most subjects were taught in the native language. Attention is drawn to the assimilation policy of the Soviet government, which instilled the Russian language in urban schools, while the declared Ukrainization concerned more rural schools in Ukraine.