The Croatian National bank is the most important financial institution in the Republic of Croatia. Through its activities and monetary policy which it pursues in purpose to preserve price stability, it influences a number of macroeconomic phenomena in the national economy. Consequently, through the regulation of the money supply, the exchange rate of the local currency and the interest rate, it affects the level of investments and savings in the economy of the Republic of Croatia. Through its interventions in times without anomalies, it maintains the continuity of price stability and the entire financial system, and in crisis situations it seeks to partially eliminate harmful consequences or completely prevent them from occurring. In the last two decades, two major financial crises have hit the Republic of Croatia– the global financial crisis in 2008 and the COVID19 crisis. With the monetary policy pursued by the central bank in response to the crises, it managed to amortize the strong impacts on the financial sector and the economy as a whole, and to prevent the transfer of negative effects from the real to the financial sector. The aim of this paper is to determine the effects that the following segments have on the stability and development of the entire financial system of the Republic of Croatia through research on the activities of the Croatian National Bank and the money supply, money market interest rates, kuna exchange rates and payment transactions.