The article discusses fundamental trends in the economic policy in the Second Polish Republic. It encompasses the most important trends, successes and failures of that policy. The Polish State during the twenty years of independence after World War I played an active part in rebuilding of the economy destroyed by the war, in strenghtening of the Polish currency, in improving agriculture and industry. Some politicians used to emphasise that this policy was pursued out of necessity and had not a programme character. However, it is out of question that the state was committed to economic issues. Undoubtedly, building of the Gdynia harbour was one of the most exceptional achievements of the Second Polish Republic.