Stability and repeatability are important factors affecting the quality of accounting earnings, because companies with regular and stable earnings have higher earnings quality compared to companies with irregular and volatile earnings. The more regular and repeatable earnings are, the easier and more reliable it will be to predict future earnings. Therefore, the aim of this study is to examine the relationship between financial flexibility and financial stability with the moderating role of environmental uncertainty. The statistical population of the study is companies listed on the Tehran Stock Exchange and the sample under study includes 152 companies listed during the years 2018 to 2022. The research method is descriptive and in terms of the relationship between variables, it is causal-correlation, 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 obtained from the hypothesis analysis showed that environmental uncertainty has a negative and significant effect on the relationship between financial flexibility and financial stability.