Commercial banks are the most significant participants in the financial system of the Republic of Croatia. Compared to other financial institutions, commercial banks are most active in the payment system and in the financial markets: monetary and foreign exchange markets and capital markets. In order to safely and efficiently achieve the functions that banks have, each bank must gain public confidence as well as the partners with which it operates. The stability of the internal and international banking system should be regarded as a matter of general interest. This public interest, arose due to the need to protect deposits, is reflected in the fact that banks are subject to control of their financial security by central bank and other official agencies. Financial statements are also subject to examination by external auditors and their opinion strengthens the credibility of such financial statements. An introduction to the financial system of the Republic of Croatia was provided at the beginning of the thesis with an emphasis on banks as the most significant financial institutions. The public publications of the Croatian National Bank show the current situation in the banking system of the Republic of Croatia. After the introduction into the banking system, the operations of banks are explained, i.e. their financial reporting. Due to the nature of their work, banks draw up specific financial statements, where is in more detail explained how banks operate and what are their assets, liabilities and capital, as well as revenues and expenditures. Once the financial statements have been put together, they should be revised, i.e. audited and given an assessment of the reality and objectivity of the financial statements. In this context, specific requirements for bank audits are described, taking into account that banks are public interest entities and are additionally supervised by the Croatian National Bank, which affects all phases of the audit process. At the end of the thesis, a segment of the audit market relating to banks was analysed to investigate market concentration and dynamics in the market. Also, the independent auditor's reports for all banks in the Republic of Croatia have been studied, focusing on the key audit matters and opinions of the auditors.