Many companies use a performance measurement system (PMS) to evaluate their suppliers' environmental performance (SEP). To do this a company can establish its own set of measures or adopt indicators borrowed from specific standards and guidelines such as the Global Reporting Initiative (GRI). However, the results of a literature review indicate that the weights of the different environmental performance indicators within an overall SEP rating are unclear. The aim of this paper is to understand what the environmental policies adopted by European manufacturing companies to evaluate their suppliers really are. In order to reach this objective, a quantitative model based on multiple linear regression has been developed. The model correlates different environmental aspects taken from the GRI set of indicators with the overall SEP rating. Interestingly, results show that performances on aspects such as transport and ISO 14001 certification do not count towards the final ranking, whereas compliance with laws and regulations is the cornerstone of the evaluation of the supplier. Other performance indicators can in some ways be linked to compliance with laws and regulations. Copyright © 2015 John Wiley & Sons, Ltd and ERP Environment