Poland is a country with scarce water resources, which places it in this regard at the end of the list of European countries. Also the capacity of retention reservoirs in Poland is very small compared to other neighbouring European countries, and does not exceed 6% of the average annual runoff from its territory. This results in the low hydropower potential. What is more, this low potential is used to a limited extent only, in contrast to most European countries. The first hydropower facilities were built in Poland in the interwar period. The development of hydropower facilities intensified in Poland after World War II. They were the low and high head plants, but also facilities with equilibrium reservoirs and reversible units. After World War II, in Poland, within its new borders, there were a lot of small hydropower plants, which initially were ignored by utility companies and were devastated. Later, they were gradually activated. The construction of new facilities, modernization of existing ones, as well as reconstruction of those degraded, are often obstructed by significant ecological restrictions. This paper presents these processes and describes the major hydropower facilities in Poland.