We conduct quasi-natural experiments to examine the effects of corporate social responsibility (CSR) on firms' stock performance amid corporate scandals closely linked with environmental and social issues. We find that firms with higher environmental and social (ES) ratings, especially those with higher S ratings show higher stock performance during the humidifier disinfectant scandal. We also find similar results using firms experiencing Volkswagen scandal in additional tests. Our findings reveal that CSR is influential over stock performance when investors pay significant attention to environmental and social issues, suggesting that firms’ investments in CSR significantly mitigate their nonfinancial risk.