Public oversight is a necessary process of the democratic systems. In order for the taxpayers of each country to be sure that public funds are used in accordance with the law, it is necessary to conduct a state audit of the spending of public funds. This is precisely the area in which supreme audit institutions act as independent external auditors. Public funds must be spent in an efficient, effective and economical way and their spending must be reported to the public. Transparency is the key to building the trust of citizens and private companies in the state system of each country. Each state is special in its own way and its operation, but also the spending of public funds, differs in many ways. Likewise, the operation of public audit is different, from the very structure of supreme audit institutions to reporting on different forms of audit. From the differences in the conduct of state audit, the supreme audit institutions of countries can learn something from each other and implement different goals and strategies if it suits them. The aim of this paper is a comparative analysis of the three types of audit, financial audit, compliance audit and performance audit, in countries that will be analyzed. The reason for the analysis of these two countries is that although the relations between the states are marked by a long history and cultural, linguistic and institutional characteristics, these two countries have many similarities and differences in the process of conducting a state audit. The types of audit and the implementation of the audits in the public sector are explained in this thesis. In addition, the characteristics and features of different types of audit are also listed. Public sector audit principles and reporting standards form the basis of effective and efficient audit performance. The main purpose of this paper is to analyze the implementation of financial audit, compliance audit and performance audit in the observed countries, and to compare the implementation of audits by supreme audit institutions to show, based on similarities and differences, which country conducts audits more effectively.