This study explores the impact of corporate tax policy on corporate social responsibility (CSR). By leveraging the enactment of the value-added tax rebate policy (VATRP) in China, we find that it has a negative effect on CSR. The results remain robust across parallel trend tests, placebo tests, propensity score matching, and a series of robustness tests. Channel analysis suggests that the expansion of investment in core business activities and the reduction in corporate misconduct explain our findings. The VATRP induces corporate hypocrisy among firms, where they engage in actions that contradict their claimed values or image of commitment to CSR. Furthermore, the negative effect of VATRP on CSR is more pronounced among service firms, highly competitive firms, non-state-owned firms, and firms with low information transparency. Our findings reveal the unintended effects of tax refunds on CSR by reshaping firms' business and financial strategies.