“Crimes against Humanity”, as guarantees of humanrights, were established in international documents such as the“Statute of the International Military Tribunal of Nuremberg”, the“Convention against Torture and other cruel, inhuman or degrading treatment or punishment”, the “Inter-American Convention on Forced Disappearance of Persons”, the “Convention on the NonApplicability of Statutory Limitations to War Crimes and Crimesagainst Humanity”, and the “Rome Statute of the InternationalCriminal Court”, all ratified by Uruguay. Nonetheless, once the lastde facto government had ended (June 27th, 1973 to March 1st, 1985),Law No. 15.848, known as Law on the Expiration of the PunitiveClaims of the State, came into force and protected those who hadcommitted “crimes against humanity”during the dictatorial government. The Inter-American Court of Human Rights annulled thisamnesty law in the “Gelman vs. Uruguay” trial, and the UruguayanParliament complied with the judgment of the Court by enactingLaw No. 18.831. However, the Supreme Court of Justice declaredLaw No. 18.831 to be unconstitutional, basing its decision on thestatute of limitations and on the principle of non-retroactivity ofcriminal law. It is the purpose of this paper to analyze the transformations that must occur in order to end impunity.