The study aimed to examine the mediated effect of income smoothing on the relationship between financial restrictions and the sustainability of dividends, positing the following research questions: "Is there a relationship between financial restrictions and the sustainability of dividends in companies listed in the Egyptian stock market?”, “Does income smoothing have a mediated effect on the relationship between financial constraints and the sustainability of dividends in companies listed on the Egyptian stock market?" Regarding the experimental aspect, the study draw on a sample of non-financial companies listed on the Egyptian stock market, amounting to 125 companies distributed over 10 different economic sectors with a total of 1875 observations. The results showed that there is a positive relationship between financial restrictions and the sustainability of dividends, supporting signal theory's suggestion that the management will seek to send positive signals to the shareholders about the current situation to maintain the confidence of the shareholders and strengthen the internal sources of funding, given the difficulties related to external financing. Furthermore, the results indicate that income smoothing has a mediated effect on the relationship between financial restrictions and dividends, which indicates that the management has appealing to earnings management methods in order to stabilize income figures, which helps it to afford the necessary dividends to send positive signals about the company's position.