Socioeconomic changes in the Eastern European socialist countries have considerably altered demographic patterns. In order to analyze these changes, a comparative study of fertility, mortality, and migration, at the regional level has been carried out. The method used is that of multiregional demography. It is shown that while the mortality patterns are more or less uniform in the regions of the five countries under consideration, the fertility and mortality patterns are more diverse, although they still correspond to the degree of the regional socioeconomic development