The article describes the less-known aspect of Stanislaw Ossowski's life - his stay and work in Lvov from December 1939 to October 1941. Ossowski came to Lvov through Bialystok, after Poland's defeat in 1939, he survived the soviet occupation there and returned to Warsaw a few months after Lvov was taken over by the Nazis. During that time he conducted his academic work in Ossolineum, where he organized the Art Cabinet and devoted his time to social sciences. Lvov also became Ossowski's meeting point with the soviet regime and its functionaries as well as with the military Nazi authorities, which enabled him to observe complicated attitudes of people towards any of the governing bodies. Ossowski filtered and analyzed these social facts and own experiences from Lvov which resulted in his formation as a scholar. The article is based on such source materials as correspondence and diaries of Ossowski, written and oral relations, archival documents and studies related to Ossowski, his environment and his circle of friends.