in this paper, the author assesses and explains changes in ethnic composition that occurred in the postcommunist countries of europe and the caucasus during the 1990s . quantitative as well as qualitative aspects of ethno-demographic changes are emphasized . Points of departure are the censuses of 1989/1992 and 1999/2004, and alternatively, the estimates of international organizations . Assessment is carried out at the state and regional levels . the current ethnic composition of post-communist europe is the result of three ethnic processes . Homogenization concerns those states with a lower initial degree of ethnic homogeneity . Polarization (the formation of two or more ethnically dissimilar entities within one state) was also a prevalent outcome . those processes were more powerful in war-stricken areas due to forced migrations and ethnic cleansing . natural increase, governmental ethnic policies and the social atmosphere played an important role in the establishment of peaceful conditions . conversely, countries that are ethnically homogeneous to a high degree recorded a decrease in their level of ethnic homogeneity . this was caused not only by immigration, but also by subjective factors .