In this paper, we investigate how the promotion incentive of politicians affects the pay gap between executives and employees in local firms. We find that the promotion incentive of local politicians significantly reduces the within-firm pay gap. This effect is more pronounced for large firms, firms in regions subject to more government intervention, state-owned-enterprises, private firms with political connections, and firms with more geographically concentrated operations. Our findings are robust to the use of the loss of top-rank political connections and economics loss due to earthquakes as instrumental variables for the promotion incentive. Furthermore, a reduction in pay gap is mainly driven by an increase in employee pay, instead of a decrease in executive pay. Overall, this study sheds light on the determinants of within-firm pay gaps from the perspective of the career concerns of local politicians.