The purpose of this research is to investigate the impact of tax avoidance on investment efficiency with emphasis on the role of institutional ownership and managerial ownership. Tax avoidance can be used as internal source of financing to enable financially distressed companies to access valuable investments with savings from tax avoidance. For this, a sample of 152 companies was selected from the companies listed in the Tehran Stock Exchange and by collecting data related to the research during the years of 2015 to 2022. The data related to the research variables for a period of 8 years were collected from reliable statistical databases. The hypotheses inspired by the title of the research were estimated according to the Chow test and the Hausman test using related statistical methods. The result of the first hypothesis indicates the existence of a significant and positive relationship between tax avoidance and investment efficiency. Also, the result of the second hypothesis showed that there is a direct and significant relationship between tax avoidance in companies with institutional ownership and investment efficiency. While the result of the third hypothesis showed that there is no significant relationship between tax avoidance in companies with managerial ownership and investment efficiency. پرونده مقاله