Purpose The purpose of this study is to investigate the value relevance of corporate social responsibility disclosures (CSRDs) in English language annual reports in Japanese companies. Based on the stakeholder theory framework, the long-term effects of CSRD on financial and market performance are examined. There is relatively little research dealing with actual CSR reporting in Japanese companies. Design/methodology/approach Using modified versions of those given by Ohlson (1995) and Ruf et al. (2001), six dimensions of CSRD based on the Global Reporting Initiative (GRI) guidelines and three different measures of performance data are used to examine the relationship between CSRDs and performance in 101 dual-language-reporting Japanese firms. Findings The paper finds that the more a company discloses CSR on labour, human rights and product safety and health in the company’s annual report, the more it is rewarded with a higher level of financial and market performance. Originality/value To the best of the authors’ knowledge, this is the first paper to provide evidence of the incremental value of GRI-based CSRD to both financial and market performance in companies with dual-language reporting in Japan, a country with a high tendency to follow the Western practice of CSRD.