The present study examines the effect of financial asset allocation structure on audit fees in companies listed on the Tehran Stock Exchange. In this study, the statistical population includes companies listed on the Tehran Stock Exchange during the years 1398 to 1402, which were collected, extracted and examined annually from the companies' financial statements. Due to the limited number of samples, the information of all companies listed on the stock exchange in the years under study for which information was available was studied in the form of a total number of 117 companies. The present study is an applied study in terms of its purpose and a semi-experimental post-event research in the field of accounting empirical research in terms of its data collection method, which was carried out using the multivariate regression method and econometric models. In order to analyze the information, descriptive and inferential statistics, linear regression method and Eaves statistical software were used. The results of the first hypothesis showed that the allocation of short-term financial assets reduces audit costs, while the results of the second hypothesis indicated that the allocation of long-term financial assets increases audit costs.