In the context of growing concern over environmental crime, as seen by current calls for the recognition of ecocide as an international crime, the European Commission is undertaking a major review of Directive 2008/99/EC on the protection of the environment through criminal law. This work builds on studies to evaluate the implementation and performance of the Environmental Crime Directive (ECD) carried out by Milieu in 2013 and 2020 respectively. The evaluation found that the ECD did not fully meet its objectives and there was room for broadening the scope of the Directive, for better cooperation and enforcement mechanisms as well as for better collection of data on efforts to combat environmental crime in the EU Member States. The study to be prepared by Milieu will focus on understanding and estimating the expected environmental, social and economic impacts of the policy options proposed by the Commission, with an emphasis on costs. It will support the preparation of an impact assessment report by the Commission that will explain and justify legal and policy action in this area.