In August 2015, the Law No. 05/l-053 on Specialist Chambers (SC) and Specialist Prosecutor’s Office (SPO) was enacted in Kosovo. The Specialist Chambers will have jurisdiction over crimes under international law and serious human rights violations committed in Kosovo between 1 January 1998 and 31 December 2000. They will apply customary international law and the substantive criminal law of Kosovo, in so far as it is in compliance with customary international law, both as applicable at the time the crimes were committed. The SC will have to determine how to address the interplay between customary international law, international criminal law and practice, and domestic legislation. This could prove especially challenging with regard to the crime of enforced disappearance, included among the crimes against humanity within the Chambers’ jurisdiction. At the same time, this crime is codified under the Criminal Code of Kosovo. The SC will therefore have to reconcile the different provisions, taking into account the continuous nature of the crime and its consequences on the application of the principle of non-retroactivity. Judges will further have to interpret the elements of the crime and the lex mitior principle in the light of customary international law and jurisprudence in a way that is conducive to accountability and to the protection of all persons from enforced disappearance.