This article addresses the issue of courts constituted by Non-State Armed Groups in a context of non-international armed conflict. In particular, it seeks to respond if an armed group such as the FARC guerrillas, which operated for more than 50 years in Colombia, i) may establish courts in the framework of a Non-International Armed Conflict? If so ii) In the light of international law, what requirements should such courts and the decisions emanating from them meet? To finally iii) analyze in the specific Colombian context, how should decisions taken by the internal courts of the FARC be assessed in the framework of the Special Jurisdiction for Peace?