The purpose of this study was to examine the institutionalization of corporate social responsibility (CSR), CSR communication, and social issue adoption of the world’s largest petroleum companies over time. Previous research on CSR and institutional theory have established that CSR is institutionalized; the current study builds on that knowledge to examine whether the social issues companies adopt as CSR may also be institutionalized and it does so from a longitudinal perspective in relation to a complete industry. Specifically, this study engaged in a textual analysis of 75 CSR reports using MAXQDA, a qualitative data analysis software, to understand how 15 of the world’s largest petroleum companies communicate about their CSR within voluntary, yet formal CSR reports from 2007-2011. Analysis of the reports consisted of three phases. First, a working schema of social issues was developed from past research and the content of the reports; this phase identified social issues that were present and prevalent in the reports. Second, data were analyzed to examine, in detail, what companies were communicating about the social issues, as well as how they were communicating about them over time. Finally, the CSR reports were coded for the institutional and/or competitive language that was used to describe the social issues within the reports. Findings indicate that social issues adopted as CSR are also institutionalized, and there are seven key and consistent social issues the companies discussed: society and community development, stakeholder engagement, environmental performance and stewardship, workplace safety and health, corporate governance, low carbon growth and technological development, and energy security, supply, and demand. Additionally, the CSR communicated by an industry over time is largely consistent with very little variation in content or format both within the same company over time and between companies over time. Further, companies utilize both iv institutional language and competitive advantage language to discuss their CSR efforts. This study extends our knowledge about CSR communication by suggesting that social issues are also institutionalized, and highlighting consistency in content and reporting over time, thereby indicating that institutionalization occurs at the macro, meso, and micro-levels of organizing.