The main objective of this thesis is the analysis of the system of public oversight of auditing in the Republic of Croatia and other member states of the European Union. It is important to have a good knowledge of the law and regulatory framework of the European Union in order to effectively carry out public oversight of the audit and to check the quality of the audit work, but also knowledge of the national requirements of the member states of the European Union. In addition to the systematization of regulatory requirements, the paper provides an insight into the development of the system of public oversight of the audit in the Republic of Croatia and other member states of the European Union, as well the comparison and interconnection of these systems. Empirical research shows that oversight of auditors affects the quality of work of certified auditors in the Republic of Croatia and that certified auditors consider deficiencies of previously conducted oversights to improve the quality of future supervision. Empirical research was conducted using the online anonymous questionnaire on the territory of the Republic of Croatia for a targeted group of certified auditors. The sample consisted of 29 filled questionnaires (15.2%). Certified auditors in the Republic of Croatia consider that the public oversight of the audit by the national public oversight body, positively contributes to the quality of the audit. Most respondents believe that the greatest disadvantage in oversight is that only formal documentation is evaluated, which is a precondition but not a sufficient indicator of the quality of work. As a major disadvantage, it is considered that the accuracy and objectivity of the financial statements are not at the centre of the supervisor's attention when conducting the supervision, which undermines the confidence of supervised entities in the process of public oversight of the audit. Respondents also believe that the public oversight body should hold more workshops or consultations on the failures observed in the field. According to research findings, it is concluded that the key factor of public oversight, which affects the quality of the auditor's work, is the method of supervision by the supervisory authorities. If the supervised entities have confidence in the work of bodies of public oversight, they will attempt to carry out the statutory audit with the highest level of quality. Also, as one of the factors is clearly established control system, which defines criteria that the supervised entities must adhere to contribute to the quality of the audits. There should be more examples of the practice, the guidelines and quality education on the best practices of auditing. In conclusion, research has shown that public oversight affects the quality of work of certified auditors, so there is a great need for continued development of the public oversight system and the audit profession itself.