Demographics of Poland
According to GUS, about 38,325,000 people live in Poland, however, the same report states that the number of residents living in the country all the time is approximately 37,200,000; with 1,125,000 people living abroad for 6 to 7 months or more. It means that the permanent population may be correspondingly smaller.
Demographic history of Poland
Before World War II, a third of Poland's population was composed of ethnic minorities. After the war, however, Poland's minorities were mostly gone, due to the 1945 revision of borders, and the Holocaust. Under the National Repatriation Office ("Państwowy Urząd Repatriacyjny"), millions of Poles were forced to leave their homes in the eastern Kresy region and settle in the western former German territories. At the same time approximately 5 million remaining Germans (about 8 million had already fled or had been expelled and about 1 million had been killed in 1944-46) were similarly expelled from those territories into the Allied occupation zones. Ukrainian and Belarusian minorities found themselves now mostly within the borders of the Soviet Union; those who opposed this new policy (like the Ukrainian Insurgent Army in the Bieszczady Mountains region) were suppressed by the end of 1947 in the Operation Vistula.