Financial performance is a very important criterion for evaluating the company's status among users of financial statements and other stakeholders of companies; therefore, improving and improving the company's financial performance has always been a challenging issue for companies and managers, and in the meantime, academic researchers are constantly seeking to identify factors that provide the basis for increasing the volatility of the company's financial performance. Therefore, the purpose of this study is to examine the relationship between audit complexity and performance volatility. The statistical population of the study is companies listed on the Tehran Stock Exchange and the sample under study includes 160 companies listed during the years 2019 to 2023. The research method is descriptive and in terms of the relationship between variables, it is causal and effectual, and in terms of the purpose, it is applied and in terms of the event, it is post-event. The regression method and panel data as well as the fixed effects model were used to process and test the hypotheses. The results of the analysis of the research hypothesis showed that audit complexity has a positive and significant relationship with performance volatility.