As the focus of environmental policy and management shifts from cleaner production at the process level towards greener products as a whole, stakeholders ask for transparency throughout the entire value chain. This article assesses the comprehensiveness and the value of currently reported quantitative environmental disclosures of 97 listed companies from the automotive, banking, pharmaceutical and electronic hardware sectors. Findings indicate that quantitative environmental disclosures have many limitations, including incompleteness and inconsistency regarding corporate activities and sites, and limited internal data coherence. For many sectors, corporate disclosures only cover a very small share of the total environmental burden of products. A stepwise procedure is proposed to verify and improve the quality and completeness of reporting using life cycle approaches. We present simple data quality tests, and we introduce the concept of the environmental influence matrix, which provides a solid basis for the identification and prioritization of key performance indicators and areas of action. Copyright (C) 2009 John Wiley & Sons, Ltd and ERP Environment.