We contribute to the literature on firms' responses to institutional pressures and environmental information disclosure. We hypothesize that CEO characteristics such as education and tenure will influence firms' likelihood to voluntarily disclose environmental information. We test our hypotheses by examining firms' responses to the Carbon Disclosure Project (CDP) and find that firms led by newly appointed CEOs and CEOs with MBA degrees are more likely to respond to the CDP, while those led by lawyers are less likely to respond. Our results have implications for research on strategic responses to institutional pressures and corporate environmental performance. Copyright © 2013 John Wiley & Sons, Ltd.