Marine litter has been identified as one of major threats to marine ecosystems due to its environmental, economic, safety, health, and cultural impacts. The paper analyses the sources of marine litter and the obstacles to resolving the issue of pollution by marine litter. It addresses the quality of the national waste management concept as well as the efficiency of its implementation in the Republic of Croatia where the Adriatic Sea is subject to substantial pressure from littering. Resolving the problem of marine litter means adopting appropriate policy regarding waste generated at sea, marinas, cruising and fishing, and at land in line with circular economy principles. Findings of the study show that the country should be proactive in adopting policies to reduce and modify packaging and link the bioeconomy to the circular economy in achieving environmental and economic benefits in terms of materials and energy efficiency. Further research concerning all Mediterranean countries should integrate, in a holistic manner, municipal waste management, food packaging and food waste, marine litter, tourism, local agriculture, and local economies.