Readability affects investor decisions. And low readability probably impedes investors' understanding of financial reports. Users of financial statements, especially investors, evaluate the information provided by companies to meet their information needs and make the right decisions. If this information is to be useful in decision making, they must be able to understand it. The value of information contained in the text is only fully recognized if the readability of the text is high. Audited financial statements can provide investors and creditors with the assurance that reliable and reliable information is provided to them, thus auditing financial statements can create economic value added for a company. Therefore, the purpose of this study is to investigate the impact of financial report readability on audit fees of listed companies in Tehran Stock Exchange between2012-2019. Multivariate linear regression and combined data were used to test the hypothesis. Hypothesis test results showed that financial report readability had a significant and inverse relationship with audit fees. In other words, the higher the financial report readability, the lower the audit fees, and the lower the financial report readability, the higher the audit fees.