Banks can be highlighted as the most important segment of the entire financial system, especially for the reason that the stability of the financial system directly depends on the operation of banks within the framework of a particular country. Although in principle the activity of banks that will encourage the expansion of the national economy is encouraged, using the example of the last global financial crisis, it is possible to point out that excessive granting of loans can ultimately be counterproductive. That is, at the moment when it becomes impossible to collect claims on loans, the operations of banks can be threatened, which can ultimately have a very negative effect on the entire economy of a particular country. In the Republic of Croatia, the CNB is in charge of supervising the banking system, which grants approval for the operation of banks in the Republic of Croatia, and at the same time supervises their operations. In addition, the CNB has numerous mechanisms with which it can influence the operations of banks, all in accordance with the current state of the national economy and future expectations, and in accordance with the defined monetary policy. The role of the CNB as a regulatory body over the banking system is increasingly visible, and this is especially evident in the conditions of certain disturbances in the financial system when it is necessary to encourage an expansive or restrictive policy, depending on the current situation.