In this study, the effect of the independence of the chairman of the board of directors on the company's risk and the cost of debt has been investigated. The present study was conducted with a descriptive correlation approach based on multivariate regression analysis. The screened statistical population includes 153 companies listed on the Tehran Stock Exchange over an eleven-year period from 2013 to 2023. The required data were collected from the Kodal website and the Tehran Stock Exchange archive. Econometric techniques and Iviews software were used to test the hypotheses. The findings of the study showed that the independence of the chairman of the board of directors does not have a significant effect on the company's risk, but it has a significant and negative effect on the cost of debt. These results indicate that in the Iranian environment, the independence of the chairman of the board of directors can be an effective corporate governance mechanism from the perspective of creditors to reduce the probability of company default; however, investors do not consider it in evaluating the company. Also, the results showed that corporate risk leads to an increase in the cost of debt, but the independence of the chairman of the board of directors can reduce or, in other words, weaken the adverse effects of corporate risk on the cost of debt. These findings have useful implications for corporate governance in the Iranian environment.