This study examines 21 environmental sustainability reports from Fortune Global 500 petroleum companies to determine how competitive advantage and institutional language is used by corporations to explain their corporate social responsibility (CSR). Results suggest the environmental sustainability discourse of the world’s largest petroleum companies contains both institutional and competitive advantage language. Also, results indicate that corporations blend the two forms of CSR communication to create a comprehensive environmental CSR profile that simultaneously enhances their position within the industrial field and offers buffering protection due to intraindustry homogeneity. Competitive advantage language is used to describe the quality, scope, and innovation of their environmental CSR as superior to other companies within their industry, particularly when communicating about technology and innovations regarding conservation efforts and manufacturing processes. Institutional language is used to describe governmental regulations and laws, industry standards for CSR reporting and expenditures, and type of CSR initiatives and partnerships. Finally, the form CSR communication takes is deeply contextualized by industry and institutional pressures as well as organizational idiosyncrasies thereby challenging the universality of CSR initiatives.