The collapse of the planned economies in Central and Eastern Europe at the beginning of this decade and the opening up of the national economies led to considerable migration flows into Western Europe. The description of earlier migration flows from Central and Eastern Europe and reasons of migration provide the basis for assessing the extent of migration to be expected after an EU-accession of individual Central and Eastern European countries. Since economic motives can be assumed to be dominant, the income development differing between Western and Eastern Europe is central to this prognosis. Rather than the destination region, the region of origin, in particular rural areas, are focused on with respect to the economic effects of migration. The developments are illustrated with the example of Poland, Hungary and the Czech Republic.