This chapter deals with the history of serialism in Central and Eastern Europe. Starting from the Polish perspective, it examines the successive stages of the response to the serial ideas in such countries as Bulgaria, Czechoslovakia, Romania, Hungary, Yugoslavia (Serbia, Croatia, and Slovenia), and the Baltic states (Lithuania, Latvia, and Estonia). The chapter draws attention to the social and political contexts of serialism’s development throughout particular periods (up to the outbreak of World War II, during the time of pressure from the totalitarian systems, and after the ‘thaw’ that emerged in the mid-1950s). It considers both the opportunities available to composers working in the so-called Eastern Bloc under the conditions of state socialism and those who worked in exile. Using examples of substantial works and influential figures, the relationship between original serial ideas and individual strategies for their transformative reception is also discussed.