The issue of governance in joint-stock companies is considered one of the fundamental problems in the business operations of contemporary companies today. Business practice often demonstrates poor and inefficient management of joint-stock companies, high fees paid to managers or supervisory board members, a discrepancy between achieved business results and management compensation, abuse of position and authority by the management body in a joint-stock company, and more. This underscores the importance of addressing the way joint-stock companies are managed and reporting on their governance. With the amendments to the Companies Act in 2007, the so-called monistic model of corporate body organization was introduced into the legal system of the Republic of Croatia. This means that a joint-stock company in the Republic of Croatia can choose to have only a management board, in addition to the general assembly, as the mandatory body of the monistic corporate organization, instead of having both a management board and a supervisory board, which are mandatory bodies of the dualistic corporate organization. From this, it is concluded that in the monistic model of corporate body organization, there is no strict formal separation between the functions of managing the company's operations and the function of supervising those operations. This explains the legal framework of the monistic model of corporate body organization, specifically the way the management and supervisory functions are organized and operate in joint-stock companies in the Republic of Croatia that have opted for the monistic management structure. As an example of good practice in the management and supervisory functions in a joint-stock company with a monistic management system, the joint-stock company Auto Hrvatska was chosen. Based on theoretical elaboration and the processed practical example, the thesis provides recommendations for possible improvements to the governance model of the joint-stock company.