In every system that strives to achieve free trade, it is necessary to balance this aim with the protection of other values. Such balancing not only has strong implications for competitiveness and economic results, but also goes to the very heart of national regulatory autonomy, constitutionalism and sovereignty. The author first discusses the way in which this issue has been dealt with in the EU in the context of Article 28 EC, and explains how the ECJ has been changing the scope of the Article as well as extending the list of possible justifications for national measures caught by it. The paper then turns to an analysis of comparable issues in the WTO. Emphasis is given to the problems of comparing these two organisations, their mutual influences and convergence. Finally, the author discusses possible approaches and tests which could accommodate free trade as well as the protection of other values.