In the modern economy, audit plays a key role in providing realistic, objective and complete information on financial statements, as well as the overall business of an enterprise. Those information later serves as a basis for making business decisions. State audit is one of the basic types of audit, and its main objective is to ensure the optimal allocation of state budget funds and to prevent unnecessary spending of funds. State audit is regulated by the Law of the State Audit Office. The State Audit Office is the supreme audit institution in Croatia, it is independent and financed from the state budget. State audit is mandatory for all organizations that are partially or fully financed from the state budget and the Croatian National Bank. Authorized state auditors must at all times adhere to the Code of Professional Ethics of State Auditors and INTOSAI Standards, which prescribe principles and rules that dictate the independence, competence, expertise, responsibility, impartiality and integrity of state auditors, and provide them with a framework for the audit process and the formation of opinions and reports. The Public Institution of the Northern Velebit National Park is obligated to state audit. The financial statements and business of the Public Institution were audited for 2017 and, based on their findings, the auditors gave an unconditional opinion on both the financial statements and the compliance of the Public Institution business.