The aim of this study is to explain the effect of strategic deviation on corporate tax avoidance and the moderating role of financial constraints and institutional ownership on the relationship between them in companies listed on the Tehran Stock Exchange. In line with the research objective, a sample of 148 companies listed on the Tehran Stock Exchange during the period 2014 to 2019 was selected. In order to test the research hypotheses, panel data regression was used in a combined method. The research findings show that strategic deviation has a positive and significant effect on corporate tax avoidance. In other words, with an increase in strategic deviation, corporate tax avoidance also increases. The results also show that financial constraints have a positive and significant effect on the positive relationship between strategic deviation and corporate tax avoidance. In other words, in the presence of financial constraints, the positive relationship between strategic deviation and corporate tax avoidance is strengthened. While, institutional ownership has a negative and significant effect on the positive relationship between strategic deviation and corporate tax avoidance. In other words, with increasing institutional ownership, the positive relationship between strategic deviation and corporate tax avoidance weakens. Accordingly, it can be concluded that corporate tax behavior is not only a function of their strategic orientations, but also financial conditions and ownership structure play a key role in shaping this behavior. The research findings can be useful for financial policymakers, regulatory institutions and institutional investors in improving financial transparency and controlling corporate aggressive tax behaviors.