Some researchers question the legitimacy of EMSs since organizations can claim to have one when in fact they make no attempt to reduce their environmental harm. In instances where EMSs enhance an organization's environmental performance, critics argue that improvements are likely to occur within the organization's operational boundaries rather than being extended throughout the supply chain. However, previous research suggests that the organizational capabilities required to adopt an EMS may facilitate GSCM implementation and the institutional pressures to adopt both management practices are similar. Consequently, EMS adopters may have a greater propensity to expand their focus beyond their organizational boundaries and utilize GSCM practices to minimize system-wide environmental impacts. This research illuminates the debate by empirically evaluating the relationship between EMS and GSCM practices. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.