Recent research has shown that costs behave asymmetrically; That is, the rate of decrease in costs when sales decrease is less than the rate of increase in costs when sales increase. This asymmetric cost behavior is known as cost stickiness. therefore; The present study investigates the effect of profit smoothing and ownership structure on cost stickiness in companies listed on the Tehran Stock Exchange. In this study, we will first examine the effect of institutional shareholders as ownership structure on cost stickiness and then the interaction effect of profit smoothing and corporate governance with cost stickiness. The statistical population of this research is formed by companies listed on the Tehran Stock Exchange and includes 85 companies active in various industries during the years 2009 to 2021. Multiple regression method has been used to test the research hypotheses. Findings indicate that ownership structure reduces cost stickiness; However, it is not a strong factor in reducing profit smoothing. The results also indicate that there is a significant positive relationship between profit smoothing and cost stickiness.