ABSTRACTThis paper investigates the relationship between various firm characteristics and environmental disclosures. Our findings evidence that firms with higher environmental ratings present a statistically significant larger size, belong to more environmentally sensitive industries as compared with firms with lower environmental ratings and disclose environmental information according to GRI guidelines. However, neither profitability nor listing status seems to explain differences in environmental disclosure practices between Greek companies. The most influential variable for explaining firms' variation in environmental ratings is size, followed by GRI reporting and industry membership. This study adds to the international research on environmental disclosure by providing empirical data from a country, Greece, where empirical evidence is still relatively unknown, extending the scope of the current understanding of the environmental reporting practices. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.