Deputy to the Sejm of the Second Polish Republic on behalf of the  Popular National Union (ZLN); Prime Minister in 1920 and again in 1923-1925. He implemented the reform of public finance; for instance, he brought about the establishment of the Bank of Poland and replacement of the mark with the Polish zloty. Grabski described his experiences from that period in his book entitled Dwa lata pracy u podstaw państwowości naszej (1924-1925). In 1926 he became the rector of the Major School of Rural Economy in Warsaw, and in 1936 he brought about the creation of the Institute of Rural Sociology, which he then headed until his death.