This paper presents an empirical investigation to study the effects of corporate governance on risk taking of private insurance firms and banks in Iran. The proposed study of this paper considers the financial information of 13 banks and 19 private insurance firms over the period 2006-2011 in Iran. The study investigates the effects of five variables including size, CEO duality task, composition of the board of directors, ownership concentration and having an internal auditing system on risk taking of private banks and insurance firms in Iran. Using some panel data and regression analysis, the study confirms the positive effect of the ownership concentration as well as negative impact of non-bound board members on risk taking.