The scholars of social responsibility have focused on identifying the factors affecting corporate social responsibility disclosure (CSRD). Corporate social responsibility is a key factor in the survival of any organization. The purpose of the study was to examine the relationship between the size of the company, ownership structure, and governance structure to explain the determinants of Corporate social responsibility in Iran. Regarding this, the data of 127 companies listed on the Tehran Stock Exchange from 2009 to 2018 were collected and analyzed. Multiple regression model as panel data and fixed effects method was used to test the hypotheses. The results from the study tests indicated that the size of the company is an effective factor in Corporate social responsibility in Iran. The role of this factor is positive. Larger companies have been more successful in Corporate social responsibility. Moreover, the ownership structure is a determining factor and has improved the disclosure of social responsibility. The presence of major owners in the company potentially enhances the dissemination of information and protects the interests of minority shareholders, and the corporate governance structure has not been a determining factor in Corporate social responsibility in Iran. Indeed, the board's ability to perform its duties decreases when its size is large.
