The number of the Jewish Diaspora in post-Soviet Russia quickly decreased under the influence of emigration, negative natural population growth, unfavorable age, gender and family structure, and assimilation. These processes emerged in the late 19th century, quite noticeably manifested itself in the Soviet era and became dramatically intense in the post-Soviet era. Russian Jews became the victim of its own progress. Since the late nineteenth century, they were and still are the most educated and the most westernized ethnic group in Russia. Their high social status ensured their standard of living, which was always above the national average. Because of this, the Jews were in the vanguard of the demographic transition in Imperial and Soviet Russia. The modern type of demographic behavior (relatively late marriages, low levels of fertility, mortality and natural growth, widespread family of birth control) is established early among them than among other ethnic groups. These features of the cultural, social and economic profile of the Jewish Diaspora was the first important reason for reducing the number of the ethnic group. Good education, high social position and westernizing of Jews also contributed to the development of assimilation, which always and everywhere occurs faster among educated and westernized ethnic and social groups. These factors led to the mass emigration of Jews in Western European countries and Israel. The Exodus of Jews from post-Soviet Russia led to the fact that the crisis elements, which slowly accumulated over the last century, reached a critical mass and has turned the difficult situation in the Jewish Diaspora to the hopeless for some 25 years.