In the 21st century, the full existence of International Criminal Law (ICL) is spoken with greater property, clarity and foundation because of a double process: the internationalization of criminal law and the criminalization of international law. Today it is conceived as a specialized branch of public international law, which has gradually evolved until reaching its institutionalization, making its precise formulation and systematization possible since it has precedent, broad practice and doctrine (basic requirements for its codification). In this article, I share some analytical-critical reflections on its specific content and differentiation from criminal international law (CIL), raising the existence of an idle discussion that has been presented in the academic, doctrinal and professional means, in the sense that both disciplines are different in name, but identical in form and substance. As such, it seeks to demonstrate that the clarification of this false debate is achieved in light of the study of the principles established in the Rome Statute of 1998, which gives rise to the International Criminal Court (ICC).