In Poland, the region where the phenomenon of multiculturalism is most strongly represented is Upper Silesia. Upper Silesia, its historical hosts, have been confronted with German, Polish and Czech nationalism since the mid-21st century. Initially, they were forced to determine their ethnic affiliation, then, due to the change of borders, they were forced to move to one or the other side of the newly established Polish-German border in 1922. After 1945, they were subjected to strong repression, deportation to forced labor camps, forced displacement, degrading verification of nationality, and then they were confronted with the Polish population who came to Upper Silesia. Most often, the Poles who arrived were hostile to the Upper Silesians. The aim of this article is to answer the question whether the experiences of integration of the indigenous population of Upper Silesia into the social, cultural, economic and political structures of the Polish state after World War II can be related to a similar process that will take place after the end of hostilities in the eastern regions of the Ukrainian state. . The starting point is the thesis that the Upper Silesian experience of the rehabilitation and citizenship verification procedures should serve as a warning against the mistakes made in Upper Silesia rather than as a useful reference point.