The purpose of this study is to investigate the effect of internal control and managerial competencies on good corporate governance by emphasizing the mediating role of quality management accounting information systems in companies listed on the Tehran Stock Exchange. This research is a descriptive survey correlation in terms of practical purpose, quantitative data type and implementation method. In this research, structural equation modeling methods and LISREL 8.8 software were used. The results of research hypotheses showed that the effectiveness of internal control has a significant effect on good corporate governance. Management competencies do not have a significant effect on good corporate governance. The effectiveness of internal control through the mediating role of the quality of management accounting information systems has a significant effect on good corporate governance. Management competencies have a significant effect on good corporate governance through the mediating role of the quality of management accounting information systems. The quality of management accounting information systems has a significant effect on good corporate governance. The effectiveness of internal control has a significant effect on the quality of management accounting information systems. Management competencies have a significant effect on the quality of management accounting information systems. Implementing good corporate governance is associated with improving corporate credibility and reputation. On this basis, good corporate governance cannot exist without internal control. Management accounting information systems through the four key elements mentioned in this study, namely integration, flexibility, reliability and efficiency can lead to greater, better and faster impact of internal control mechanisms on corporate governance in Iranian companies. Competencies of managers (knowledge and technical competence) in the company, if combined with the implementation of management accounting information systems can make corporate governance more efficient.