This chapter introduces the concept of ecocide as a legal category within international criminal law, emphasizing its relevance in the face of escalating environmental destruction worldwide. It begins with emblematic cases of environmental harm in Brazil, such as the “Fire Day” in the Amazon, and expands to global examples, illustrating the transboundary nature of ecological disasters. The chapter critically examines the absence of criminal accountability for massive environmental damage, both domestically and internationally, and proposes ecocide as a necessary addition to the Rome Statute of the International Criminal Court. It explores the historical development of international environmental and criminal law, the challenges of defining ecocide, and the legal and procedural obstacles to its recognition. The chapter also discusses the role of legal entities, the difficulty of establishing causation and intent, and the evidentiary burdens in international proceedings. Ultimately, it argues for the international criminalization of ecocide as a means to strengthen environmental protection and global justice, drawing parallels with the historical evolution of genocide and crimes against humanity.