This paper assesses the scope for and implications of trade measures for environmental purposes in the WTO and the European Union. The assessment is illustrated by a number of cases that have tested the limits of legal provisions in the WTO and EU dealing with issues arising at the intersection of trade liberalization and environmental protection such as the maintenance of domestic health, safety and environmental standards and cross-border activity. The conclusions of the paper point to a trend towards the regionalization of trade and environment rule making and implementation, with the EU moving along its distinctive policy making path, and the GATT/WTO barely moving at all. The paper demonstrates the limitations of judicial and quasi-judicial means of dealing with trade measures for non-trade purposes and argues for approaching the legitimacy of such measures through the lens of process rather than outcome, expanding participation and interest representation in national and international decision- and policy-making.