This paper investigates the impact of family ownership on information transparency of the listed companies in Tehran Stock Exchange. The populationused in this study comprises firms listed on the Tehran Stock Exchange (TSE) between 2008 and 2012. Hence, family ownership, and financial information transparency level and accounting information transparency level are considered as independent and dependent variables, respectively. There has been also used from three control variables of firm size, financial leverage and firm profitability. To test the hypotheses, Ordinary Least Squares (OLS) is used. The results indicated that there is no significant relation between family ownership and financial information transparency level of companies. Also, there is not significant relation between family ownership and accounting information transparency level.