With the development of economy and the establishment of a great number of enterprises there has occurred the need for an audit. The audit represents an independent authentication and examination of financial records, information and documents of the certain subject, the aim of which is to determine if the mentioned items show the real financial result and position. Auditing has to be consistent with all the generally accepted auditing standards, principles and methods of auditing, the most significant of which are Benford's law, horizontal and vertical analysis, and analysis with the help of indicators, Altman model and DuPont's system of indicators. To ensure reliability and objectivity of all important collected data and financial information, the auditor has to be competent and have professional skills and knowledge, be led by the general ethical principles, but also independent of all the external influences. The State Audit Office of Croatia, being a supreme auditing, professional, external and independent institution, has the obligation to perform audit minimally once a year on behalf of state. In Croatia, the jurisdiction and scope of work of the Office are regulated by the State Audit Office Act. In the practical part of the thesis the publicly declared data of the State Audit Office, in the form of the Report on the performed audit of the annual report of Croatia's state budget realization in years 2015, 2016, 2017 and 2018 have been analysed. The analysis and plan of the revenue and expenditure account, the account of financing and amendments of state budget, as well as the values in realization of state budget of the examined period of time have been conducted. Moreover, the amounts of overall budget resources have been presented also, along with the comparison of total revenues and expenditures of Croatia's state budget during the examined period of time.