Marine litter is becoming a more and more important threat to preservation of the global environment and a growing economic, health and social problem. On a global scale the problem of marine litter was first brought to the world’s attention in the 1980s, when under governance of the United Nations, first efforts were initiated in order to diminish and prevent waste from marine sources. Since then the scope of combat against marine litter has been widened due to emergence of new threats. The European Union (EU) has stood out as the global leader in development and implementation of the general environmental policy as well as in the efforts and initiatives aimed at prevention and minimization of marine litter. Adoption of the Marine Strategy Framework Directive (2008/56/EC) by the European Union has led to marine litter becoming a part of environmental legislation for the first time. Success in achievement of the Directive's goals depends on the contribution of each member state of the EU. In the context of national marine litter management policies, particular attention has been given to the analysis of marine litter policy of the Republic of Croatia. Implementation of environmental policy has been an enormous challenge for the country in general, particularly due to the necessity of huge financial investments, whilst marine litter policy is still at the beginning of its development. Specific legislation in regards to marine litter has not yet been adopted and the process of formulating a national marine strategy has been slow mostly because of a lack of human and financial capacities. The subject of researches that have been so far conducted has mostly been related to negative environmental effects caused by marine litter while economic analyses have been addressed only by few of them. Therefore the thesis is especially focused on negative economic effects of marine litter which manifest themselves in growing costs or lost revenues in sectors based on utilization of marine resources (e.g. tourism, fishery, maritime transport). On the basis of this, the thesis includes cost benefit analysis of the Adriatic Sea protection, created for the case of the Republic of Croatia.