Companies are always faced with many opportunities and need an optimal investment decision. Internal control as a governance mechanism and managerial ability as a behavioral mechanism affect the efficiency of investment. The purpose of this study is to investigate the role of internal control quality on the impact of management ability on investment efficiency. Research in terms of purpose is part of applied research and research method in terms of nature and content is cause and effect. The research was conducted in the framework of deductive-inductive reasoning and panel analysis was used to analyze the hypotheses. To collect information, data from 152 companies listed on the Tehran Stock Exchange in the period 1391-1399 have been used. The results of this study show that management ability has a positive and significant effect on overinvestment and has a negative and significant effect on underinvestment. The quality of internal control also limits the positive relationship between managerial ability and over-investment and strengthens the negative relationship between managerial ability and underinvestment.