Information on corporate risks plays an essential role in the decision-making process and in the assessment of different corporates. This study examines the effect of corporate governance mechanism on risks disclosure in companies listed in Tehran Stock Exchange (TSE). For this purpose, data from 350 firm-year over the period of 2009 - 2013 were collected by archival method. Risk disclosure data was collected by “Content Analysis” of annual reports of companies. Collected data were examined by implementing the liner regression model. The results showed that institutional investors posit a positive significant effect on risk disclosure. In addition, equity owned by the five major shareholders, duality role of the CEO and board independence have a negative significant effect on corporate risk disclosure; Findings also showed that the firm size and leverages reveals a significant positive effect on risk disclosure. However, no significant relationship was found between the percentage of equity holdings equal to, or above 5%, equity owned by the major shareholder and dividend payout ratio and risk disclosure.