Dividend policy is one of the fundamental decision areas of financial management and involves determining what proportion of a firm’s net profit will be distributed to shareholders as dividends and what proportion will be retained within the firm. Through this policy, companies aim to increase both firm value and market value. In this section, the aim is to examine the effect of cash dividend payout ratios on the financial performance of eleven shares belonging to nine banks listed in the BIST Banking Index. Using data obtained from the financial statements of the banks, dividend payout ratios based on cash dividend payments were calculated. Return on equity (ROE) and return on assets (ROA) were used as indicators of financial performance. In order to test the relationship between the variables, correlation analysis and simple linear regression analysis were applied. The findings indicate that the dividend payout ratios of Garanti BBVA, Albaraka Türk Participation Bank, and Türkiye Halk Bankası have an effect on return on assets. In addition, the dividend payout ratios of İş Bankası’s A, B, and C shares and Akbank were found to have significant effects on both return on equity and return on assets. Furthermore, the dividend payout ratio of ICBC Turkey Bank was found to have an effect only on return on equity.