This study is to provide evidence on the effect of corporate social responsibility expenditure and board national diversity on corporate value. We also test the role of the availability of sustainability reports as a moderating variable on this relationship. Our samples are Indonesian-listed companies on the Indonesia Stock Exchange from 2011 to 2020. Tobin's Q is used to measure firm value. The CSR expenditure is measured by the amount of CSR expenditures reported in the annual report. In contrast, the board’s national diversity is measured by the company’s ratio of foreign board members. The availability of sustainability reports is a dummy variable. The results suggest that CSR expenditure and board diversity do not affect firm value. Moreover, the results indicate that the availability of sustainability reports has a negative moderating effect on the relationship between the ratio of foreign commissioners and firm value, and, on the contrary, has a positive impact on the relationship between the ratio of foreign members of the board of commissioners and firm value. We may imply that companies with a high proportion of foreign member boards of commissioners and provide sustainability reports have higher firm value than companies that do not provide sustainability reports. Our study suffers from some limitations. First, most of our samples do not have foreign commissioners on their board. Second, the Indonesian authority does not strictly regulate the disclosure practices of CSR-related expenditures. Third, future researcher may use another measure of sustainability report, like the quality of the report.