Multiple factors – demographic, social, cultural, and political – determine specific patterns of ageing and policy responses to corresponding challenges and opportunities. This chapter will focus on the above factors in two groups of Eastern European countries: the former Soviet Union countries of Europe (Belarus, Moldova, the Russian Federation, and Ukraine) and Western Asia (Armenia, Azerbaijan, and Georgia), as well as in the Western Balkan States that do not belong to the European Union (Albania, Bosnia and Herzegovina, Montenegro, Northern Macedonia, and Serbia). The review and discussion will be devoted to the characteristics of population and individual ageing in two groups of Eastern European countries. Particular attention will be paid to the participation of these countries in the process of implementation of the Madrid International Plan of Action on Ageing and its implementation strategy for the region of the United Nations Economic Commission for Europe.