Public procurement and its regulation is without a long-standing tradition in Croatian law. It was first regulated in 1995 when Croatian Government passed the Decree on the procedure for procurement of goods, services and contracting in the Republic of Croatia. This thesis portrays the system of public procurement according to the new Law on public procurement (Official Gazette of Croatia, 120/16) with an emphasis on open tendering. The beginning of the thesis explains aims, principles, clients, Procurement Plan and Register of deeds. Following the above mentioned is a brief explanation of all public procurement procedures and entire implementation of open tendering with case history of open tendering of protection services for persons, objects and property of Croatian Bank for Reconstruction and Development and the services of Central Alarm System. The final part of the thesis processes data on the efficacy of Croatia’s public procurement system and concludes that the mentioned system is inadequately developed, while the entry into force of Law on public procurement (Official Gazette of Croatia, 120/16) attempts to harmonise public procurement system with Acquis Communautaire and through the simplification of procedures significantly influence the reduction of costs in the economy.