Abstract: This paper examines the patterns in voluntary environmental disclosures made by a sample of large UK companies. The analysis distinguishes between the decision to make a voluntary environmental disclosure and decisions concerning the quality of such disclosures and examines how each type of decision is determined by firm and industry characteristics. We find that larger, less indebted companies with dispersed ownership characteristics are significantly more likely to make voluntary environmental disclosures, and that the quality of disclosures is positively associated with firm size and corporate environmental impact. We find significant cross-sector variation in the determinants of both the participation and quality decisions. Furthermore, the manner of this variation differs between the two.