This article examines transnational environmental networks as an important and thus far under‐studied mechanism that can influence the pathways toward compliance with European Union (EU) legislation in new Member States. The argument stipulates that transnational networks, on balance, increase the capacity and political leverage of Central and Eastern European states and societal actors to activate management and enforcement paths to compliance with EU environmental norms. The theoretical framework specifies the network assets and the mechanisms through which they can support the two paths to compliance. In the empirical section, this framework is used to examine the impact of transnational environmental networks on the compliance with EU biodiversity directives in two of the most recent Member States: Bulgaria and Romania.