We analyze how demographic, geographic and economic factors affect the size of bilateral Asian migration flows. Our analysis is conducted in three strands to differentiate between the role of factors on 1) migration flows amongst Asian countries, 2) from Asian countries to destinations outside the region and 3) towards Asian countries from elsewhere in the world. We exploit new estimates of five-year bilateral migration flows between 1990 and 2015 in two rounds to study the Asian region as a whole and sub-regions of Asia. During this period of time, we find that migration flows within Asia have nearly doubled. There are also distinct differences in the geographic, social, economic and demographic factors associated with large migration flows within, from and towards Asia.