The article assesses the impact of the European Union’s CRD IV/CRR capital requirements package - comprising the Capital Requirements Directive IV and the Capital Requirements Regulation - on the liquidity of cooperative banks in Poland. The author analyzes the regulations in question and examines cooperative bank data using statistical methods. The analysis finds that cooperative bank deposits in Poland are stable despite a crisis of confidence on the interbank market. The research also shows that there is a significant regulation mismatch in terms of the structure and nature of Poland’s cooperative banking sector. The author concludes that the new regulations are set to bring positive changes to cooperative banks in Poland, which may be essential for their future operation and development.