AbstractThis paper investigates whether and how controlling shareholders' value (i.e., the concentration of controlling shareholders' wealth within a business group) affects corporate tax planning using Korean chaebols. We find that firms with high controlling shareholders' value engage in a lower level of tax avoidance than other affiliates in the business group. We also find that controlling shareholders' concern about the costs of tax avoidance (i.e., regulatory penalties and reputational damages) are potential mechanisms that prevent firms with high controlling shareholders' value from aggressive tax planning. Lastly, we provide the value implication of tax avoidance for firms with high controlling shareholders' value.