In the present study, with regard to the important role of the directors in the success of companies and the importance of managers' decisions and powers in the company's functional framework, as well as the importance of return on equity for investors, which is undoubtedly influenced by the decisions of managers, the relationship between directors' discretion, the operational net assets and stock returns in accepted companies in Tehran Stock Exchange has been investigated. The statistical population of this research consists of 126 companies accepted in Tehran Stock Exchange during 2011-2016. The required data is collected from the 'Rahavard Novin' database. The analysis and testing of research hypotheses along with their results, were made according to the outputs obtained from Eviews software version 9. Finally, the results of the research indicate that according to the main hypothesis, the operational net assets have a direct and significant effect on the stock returns of companies. Also, according to the first and third sub-hypotheses, investment decisions and profit sharing decisions have a direct and significant effect on the relationship between the operational net assets and stock returns of companies. Also, according to the second sub-hypothesis, financing decisions have a reverse and significant effect on the relationship between the operational net assets and the stock returns of companies.