Stanislaw Sierotwinski (1909-1975), a librarian, historian of literature and bibliologist, played a key role in protecting and recovering various library collections following the end of the Nazi occupation of Poland. Between 1 December 1945 and 30 April 1947 he worked as the Ministry of Education delegate for the protection of abandoned and deserted libraries. His office was in Cracow and he supervised an area divided into six districts: Gdansk, Olsztyn, Szczecin, Wroclaw, Cracow and Lubuski districts. In his work he focused mainly on the Western and Northern Territories (the so-called Recovered Territories, regions incorporated into Poland after WWII). Between 1 December 1945 and 31 December 1946 he tracked down and recovered around 5.5m books, 1.8m of which were transported to Cracow. He was particularly active in Lower Silesia, where he saved over 2m books. He brought to Cracow around 1.7m books (over 90% of them of German origin) from that region. Saving such a huge number of books which had been stolen or nearly destroyed was a great achievement, particularly if we take into account the difficult conditions in which Stanislaw Sierotwinski worked. His small team had just a few lorries at their disposal and meagre financial resources. The problems outlined in the present article do not exhaust the subject. They just demonstrate that there is a need for in-depth research concerning the protection and recovery of library collections after the Second World War.