The lecture aims to provide an overview of the concept and the specific characteristics of the EU Environmental Law in order assess its effectiveness in terms of contributing to the protection of the environment and promoting sustainable development at the EU level. To this end, the evolution of the EU Environmental Law, as illustrated in successive phases, will be analyzed first. Then the emphasis will be shifted to the relevant Sources (Treaties, Directives and Regulations) and to the competence of the EU to deal with the environmental matters (“shared competence”). The lecture will also outline the basic principles of the EU Environmental Law, focusing specifically on the precautionary principle, the polluter pays principle and the integration principle, also in the light of the relevant CJEU jurisprudence.  Furthermore, the lecture will deal with the instruments introduced for achieving the objectives of the EU Environmental Law and with the given enforcement mechanisms.  It will conclude with an assessment of the effectiveness of the EU Environmental Law and some of the challenges that it faces.