The disclosure of corporate environmental performance is an increasingly important element of a firm’s ethical behavior. We analyze how the legal origin of foreign institutional investors affects a firm’s voluntary greenhouse gas emissions disclosure. Using a large sample of firms from 36 countries, we show that foreign institutional ownership from civil law countries improves the scope and quality of a firm’s greenhouse gas emissions reporting. This relation is robust to addressing endogeneity and selection biases. The effect is more pronounced in firms from non-climate-sensitized countries, for which the gap between firms’ environmental standards and investors’ environmental targets is potentially larger, and in less international firms. Firms with a higher level of voluntary greenhouse gas emissions disclosure also exhibit higher valuations.