In 1947, the communist regime in Poland forcibly resettled about 140,000 Ukrainians and Lemkos from their traditional homeland in southeastern Poland to the north and west of the country (formerly German territories). This massive relocation program is known as 'Operation Vistula'. The communists' intention was to build a nation state. Over 21,000 of the deportees settled in Lower Silesia. The author discusses the principles under which the Ukrainians and Lemkos were settled in the new territories in Lower Silesia. The article is mainly based on author's own detailed archival research. It presents new data on the size and distribution of these populations in Lower Silesia and focuses on the following aspects: the distribution of the Ukrainians and Lemkos in Lower Silesia after 'Operation Vistula' in 1947, some problems with the distribution of the relocated people in 1947 and 1948, administrative resettlements in Wroclaw Voivodeship in the summer and autumn of 1948, major changes in the distribution of the Ukrainians and Lemkos population in the second half of 1948, as well as after the Polish administrative reform in 1950.