The purpose of this assistance activity, organized by the Arias Foundation for Peace and Democracy in cooperation with the Costa Rican Ministry of Foreign Affairs, was to host Argentina's Ministry of Foreign Affairs, the Argentinean National Agency for Controlled Materiel (ANMAC), and the Argentinean Ministry of Defence for them to share its experience implementing the Arms Trade Treaty (ATT). The main topics were twofold: (i) the Argentinian experience in arms transfer, recounting the judicial, procedural and administrative processes as well as control list and internal commerce; and (ii) the nature of the authority in charge of arms transfer processes, delineating the functions, conformation and workings as well as good practices and recommendations.