Between 2009 and 2011, the comprehensive Law on Weapons and several subsequent sub-legal acts on weapon market control came into force in Kosovo. The new system replaced the old UNMIK regulations that seemed not be effective in such postconflict zone as this part of Balkan region. The main objective was to enhance the control over the weapon market for civilian use, limit the illegal possession of weapon in Kosovo and improve the effectiveness of law enforcement bodies performance in the field of combating illegal weapon trafficking. One of the elements of the system was appropriate marking of firearms, their parts and ammunition. Authors of this article do not address the overall efficiency of the weapon control system, but analyze Kosovo’s requirements for marking of weapons from the perspective of international standards. Marking of weapons is perceived as one of the three main pillars for effective tracing of weapons (marking, record-keeping and exchange of information) that allows to examine the background of firearms and, in certain cases, also parts of firearms and ammunition. Marking also allows to preserve strict control over the firearms in private hands by linking the producer, dealer and owner of the particular firearm. Markings on firearm shall also depict all major changes to the status of weapon (e.g.: proof marking, deactivation marking, transfer from government stocks or import). The article refers in detail to all the methods and requirements on marking.