The purpose of this study was to analyze which dimensions of non-financial environmental responsibility information are more reflected in credit ratings. The non-financial environmental responsibility information used in this study was environmental strategy, environmental organization, environmental management, environmental performance, and stakeholder communication. Based on 1085 companies listed on the Korean capital market from 2013 to 2018, this study reports that the more companies engage in environmental responsibility activities, the better their credit ratings are. Specifically, it found that companies with higher environmental performance and stakeholder communication activities received better credit ratings, while higher environmental management and environmental strategy scores had a relatively weak influence. This indicates that among the corporate environmental responsibilities, the more activities requiring relatively little discretion from managers are performed, the more the reputation capital that is accumulated through corporate environmental responsibility (CER) activities, which leads to higher credit ratings. These associations were found to be strengthened in an information environment where there is a higher degree of information asymmetry and the lifecycle of a firm is at a maturity stage.