The concept of participation was neglected for so many years at the European level, and has been rediscovered in the context of several developments during the 1990s: the move away from communitarised policies, the process of enlargement, and the crisis of the European Commission of 1999. In the Commission's rhetoric, the notion clearly contributes to legitimise EU policies, but many critical voices have been raised as to its actual impact. Thus, participation in European policies still needs to be investigated if we are to understand how Europeanisation happens in practice. With a view to addressing this gap, Tulmet's chapter investigates the role of social actors in the process of Europeanisation (top-down) and of integration (bottom-up) in the field of environment policy in Estonia and Hungary. The case study highlights the differentiated impact of EU accession on and the role national social actors play in this respect. It demonstrates that in the context of enlargement, the term Europeanisation is not necessary a synonym of cognitive harmonisation, but rather of institutional and organisational adaptation on the narrow pathway of legacies of the past.