This article analyses the emergence of an environmental policy of the European Communities (EC) in the 1970s in terms of the Europeanisation of the environment. Drawing on the conceptual literature on Europeanisation, three different types of Europeanisation are distinguished: first, Europeanisation as establishment of institutions and policy making at the EC-level, secondly, Europeanisation as the EC's impact on the member state, and thirdly, societal Europeanisation, as a process of establishing transnational cooperation of societal actors across the EC. The article disentangles the process of Europeanisation of the environment emphasising the beginnings of Europeanisation in the context of the Council of Europe and the take-over by the EC of policy ideas and principles from the international level. Furthermore, it addresses the rapid emergence of societal Europeanisation, notably by anticipating the European impact on member state legislation.Elaboré à l'échelle internationale, le concept politique d'environnement offre l'exemple rare du transfert d'un domaine d'action politique vers les Communautés européennes depuis d'autres internnationales. Cet article explore le processus complexe d' de la politique environnementale, comme un transfert à directions multiples d'un concept forgé dans les années 1970.