Unethical behavior and corruption are nowadays increasingly present features of the public sector. They are a serious problem that greatly threatens the trust of citizens and leads to numerous consequences for society as a whole. The consequences of inadequate prevention of unethicality and corruption lead to economic instability, poor management of public resources and significantly impaired quality of public services. Accordingly, preventing and fighting against such forms of behavior requires the participation of all stakeholders in society, the existence of strict laws and regulations, as well as efficient monitoring and sanctioning mechanisms. In addition to legal regulation, it is necessary to promote responsibility and honesty and strengthen the awareness of the importance of ethical behavior in the public sector. Supreme audit institutions, as public bodies that carry out the state audit of a particular country, significantly contribute to the achievement of the ethics of the public sector, that is, its institutions. By independently evaluating financial statements and various processes, supreme audit institutions identify potential irregularities, abuse or corruption and then inform the government and other relevant stakeholders about these findings. Equally, their role includes providing advice for improving internal control systems, so that these systems can appropriately reduce the risk of various forms of unethical behavior. In addition, they educate public officials about the importance of transparent and responsible business, which is in accordance with applicable laws and regulations. In fulfilling all these tasks, they are obliged to comply with the appropriate legal and ethical framework, i.e. numerous standards and guidelines regulating their activities. Through analyzing the roles and tasks of supreme audit institutions, as well as based on the results of two conducted surveys, this paper will examine their contribution to the ethicality of the public sector.