Abstract It is widely accepted that board leadership structure and whether the chairperson and CEO roles should be undertaken jointly or separately affects the performance of a firm. Despite this consensus, empirical evidence presents major uncertainties as to the direction and degree of this influence. This study contributes to this debate by examining the relationship between board leadership structure and firm performance and the expense ratio, using propensity-score matching methods for Chinese PLCs from 2003–2010. It is reported that whilst CEO duality is not related to companies' profitability ratios, it is linked to a higher expense ratio compared to matched companies with a separate board leadership structure. This indicates that a separate board leadership structure is an effective corporate governance arrangement to reduce agency costs for Chinese PLCs.