The purpose of the paper is to consider the Lviv period of the life of Professor Ryszard Gansiniec (1888-1958) based on the analysis of historical sources. Scientific novelty. A number of archival documents were introduced into scientific circulation, which made it possible to find out the conditions in which the scientific and pedagogical activities of Professor Ryszard Gansiniec took place at Lviv University. Conclusions. Professor Ryszard Gansiniec made a great contribution to the creation of a modern school of classical philology in Lviv. The Lviv period of his life was a quarter of a century and was an important stage of his scientific and pedagogical activity. In addition to working at the university, he also performed various public duties and edited a number of scientific journals. The circle of his scientific interests was quite wide, but he was primarily interested in various aspects of the development of ancient religions, especially ancient Greek religion and magic. The Second World War prevented the realization of many scientific plans of the scientist. In the difficult realities of wartime, he had to work outside his profession to feed his family, who moved to a safer place as the front line approached. The liberation of Lviv from the German occupation gave hope for the establishment of a peaceful life, the restoration of scientific and pedagogical activities at the University of Lviv. However, like many other representatives of the Polish and Ukrainian intellectuals, Professor Gansiniec had to go through imprisonment and fight for the return of his home and belongings. Among other things, the scientist's diary was lost, which he had to destroy with his own hands during the search. For a long time, the scientist did not want to leave Lviv for Poland, but he made such a decision when it became obvious that there was no hope of preserving Polish Lviv, and leaving for Poland was the only possibility to reunite with his family. It is obvious that this difficult decision was justified under those conditions and allowed Ryszard Gansiniec to continue his fruitful scientific and pedagogical activities.