This study was aimed to investigate the relationship between managerial overconfidence and cost stickiness at the Tehran Stock Exchange. The statistical population consisted of 127 companies trading at the Tehran Stock Exchange from 2009 to 2013. In order to separate cost stickiness as a dependent variable, the variables of general and administrative cost stickiness, cost of goods sold, and selling and distribution costs were used. According to the results, it can be concluded that managerial overconfidence has a significant positive relationship with general and administrative cost stickiness, selling and distribution costs, and cost of goods sold. In other words, the lower managerial confidence is, the lower cost stickiness will be. The results also indicated that combining the variables of sales intensity, sales, and managerial overconfidence as well as sales intensity, sales, and representation theory had no significant impact on selling and administrative cost stickiness, cost of goods sold, distribution, and sales.