This article outlines the history of the Father Siemaszko Educational Institution in the interwar period. At that time it was located in three centres: in Krakow at Długa and Prądnicka Streets and in Czerna. It was one of the largest educational and welfare institutions in Poland at that time. By the end of the 1930s it was caring for more than 450 boys. About 280 of its graduates went to work in various workshops, 45 graduated from secondary schools as teachers, clerks and technicians, 14 former pupils of the Institute became priests.