In this thesis the main reasearch subject is marine litter and its distribution on the island of Lokrum which is situated in the southern Adriatic sea, near the city of Dubrovnik. The research was conducted at multiple locations on the island ranging from ports, hard to access areas such as rocky shores and cliffs, to accessible beaches mainly used by visitors. Cleanup activities were organised in two different time periods: the first one in april 2017., and the second one in september 2018.. In these two cleanup activities the types and the weight of marine litter that was collected on each of the locations were obtained. It has been noticed that a few factors have impact on the distribution of marine litter, such as the potenitial of the location to be used by the public in the form of recreational activities (beaches), or in the form of using the location as a port, and the exposure of locations to sea currents. The results from this research imply that there is a difference between the amount of the collected marine litter in april 2017. and in september 2018., notably more marine litter was collected in september 2018. than in april 2017.. The differences in types of marine litter collected in both cleanup activities were minimal.