It is becoming ever more apparent that the enforcement of environmental law is a key problem of environmental law and policy. While the number of legal instruments at international, European and national level continue to increase, the actual enforcement of the relevant law remains insufficient, seriously impairing the effectiveness of environmental law.Based on the assumption that nothing undermines the credibility of public authorities more than law that is not applied, this research review analyses the most important articles on the enforcement of international, EU and national environmental law that approach the issue from multiple angles and endeavour to provide solutions for improvement. The review will be a valuable tool for scholars and practitioners as it provides acute insight into existing concerns and intends to stimulate discussion on possible ways to reform and bolster environmental law enforcement.