In this article we aim to verify the hypothesis that international cooperation in criminal matters will strongly rely on the national design of the regulation and enforcement of environmental law (incriminations, authorities, powers). Second, if this is the case, does it create particular problems that undermine the effectiveness of environmental protection through criminal law in this field? For answering these questions we propose to analyse, first, the relationship between the international environmental regulation and the international enforcement obligations. Second, we have to verify whether and to which extent the international norms on judicial cooperation in criminal matters relate to environmental enforcement. Finally, we will conclude with some recommendations to remedy the particular problems.