University of Tehran Financial Research Journal 1024-8153 22 2 2020 07 22 Associate Prof., Department of Finance, Faculty of Management and Economics, Urmia University, West Azarbaijan, Urmia, Iran. Associate Prof., Department of Finance, Faculty of Management and Economics, Urmia University, West Azarbaijan, Urmia, Iran. 227 248 77149 10.22059/frj.2020.279145.1006855 FA Gholamreza Mansourfar Associate Prof., Department of Finance, Faculty of Management and Economics, Urmia University, West Azarbaijan, Urmia, Iran. Samira Joudi MSc., Department of Accountin, Faculty of Management and Economics, Urmia University, West Azarbaijan, Urmia, Iran. Ehsan Poursoleiman MSc., Department of Accountin, Faculty of Management and Economics, Urmia University, West Azarbaijan, Urmia, Iran. Journal Article 2019 04 13 <strong>Objective:</strong> This research is aimed at investigating the impact of internal and external corporate governance on the relationship between information asymmetry and investment efficiency. <strong>Methods:</strong> For the purpose of analyzing the research hypothesis, 106 publicly traded firms on the Tehran Stock Exchange, between 2009 and 2018, have been selected using the elimination method. The analysis of the hypotheses was carried out by using a multivariate regression model with panel data method and employing the fixed effects approach. <strong>Results:</strong> According to theoretical bases and research finding, information asymmetry has a negative and significant relationship with investment efficiency. Also, corporate governance variables, in both external and internal governance, and both variables of information asymmetry and both dimensions of corporate have a positive and significant relationship with investment efficiency. <strong>Conclusion:</strong> The results of the research show that the existence of asymmetric information and ambiguity in financial information may lead to inefficient investments. Hence, one of the ways to reduce information asymmetry and increase investment efficiency is enhanced corporate governance quality. According to the existing principle, current expectations, and the findings of this study, the interaction of information and corporate governance have a positive and significant relationship with investment efficiency. This means that in the condition of information asymmetry, the existence of internal and external corporate governance reduces inefficient investments and urges managers to make optimal and efficient investment decisions. <strong>Objective:</strong> This research is aimed at investigating the impact of internal and external corporate governance on the relationship between information asymmetry and investment efficiency. <strong>Methods:</strong> For the purpose of analyzing the research hypothesis, 106 publicly traded firms on the Tehran Stock Exchange, between 2009 and 2018, have been selected using the elimination method. The analysis of the hypotheses was carried out by using a multivariate regression model with panel data method and employing the fixed effects approach. <strong>Results:</strong> According to theoretical bases and research finding, information asymmetry has a negative and significant relationship with investment efficiency. Also, corporate governance variables, in both external and internal governance, and both variables of information asymmetry and both dimensions of corporate have a positive and significant relationship with investment efficiency. <strong>Conclusion:</strong> The results of the research show that the existence of asymmetric information and ambiguity in financial information may lead to inefficient investments. Hence, one of the ways to reduce information asymmetry and increase investment efficiency is enhanced corporate governance quality. According to the existing principle, current expectations, and the findings of this study, the interaction of information and corporate governance have a positive and significant relationship with investment efficiency. This means that in the condition of information asymmetry, the existence of internal and external corporate governance reduces inefficient investments and urges managers to make optimal and efficient investment decisions. https://jfr.ut.ac.ir/article_77149_2ce08e51a062139240ab7bcdd2c37209.pdf