This article investigates the impact of the 2011 Great East Japan Earthquake on investor responses to corporate social responsibility (CSR) activities in Japan. Employing Propensity Score Matching and Difference-in-Differences analyses, we analyse investor reactions to both positive and negative CSR news pre- and post-earthquake. Our results indicate a significant increase in share prices for firms that reported positive CSR news post-earthquake, thereby highlighting a heightened investor value on CSR during times of crisis. In contrast, negative CSR news showed a more pronounced negative effect in longer term windows. Additionally, industries directly affected by the earthquake experienced a substantial shift in investor sentiment towards negative CSR news. These findings enhance the understanding CSR’s tole in investor behaviour during crises and offer insights into effective corporate strategies in disaster-prone contexts, particularly in Japan’s unique cultural and economic landscape.