This article compares the use of litigation to enforce species protection law in the European Union (EU) with that of the United States (US). Recent legal disputes over wolf hunting on both continents offer useful case studies. Focusing on three aspects of litigation – namely, (i) against whom claims are brought, (ii) who can bring claims, and (iii) the types of claim that can be brought – the analysis contrasts US-style adversarial legalism with its European counterpart, or ‘Eurolegalism’, and assesses what each approach is able to deliver in terms of the legal protection of wolves. It is argued that Eurolegalism helps to explain the development of species protection law in the EU and its similarities to and differences from the American experience.