Stupica Mala Bay is located on the SE part of the Žirje Island, the most remote inhabited island of the Šibenik island group. Three sediment samples from the beach in Stupica Mala Bay, A (upper intertidal), B (bottom intertidal) and C (marine sample), were defined with granulometric characterization as sandy gravels, and moving from the beach to the sea there is a particle size reduction. The samples have a high carbonate content, which decreases with particle size reduction. Results of the mineral composition analysis of sediment sample A showed that the sediment contains calcite, magnesium calcite, aragonite, and quartz. The content of organic matter in sediment is 1,07 %. From the fraction of material > 4 mm which was sampled from the dry part of the beach, 0,47 g of plastic particles per 1 g of sediment were separated. Results of the polymer composition determination of 71 plastic particles larger than 4 mm, showed that 68 % particles are composed of low-density polyethylene, 21 % are polypropylene particles, 3 % particles are polystyrene and polymer composition of 8 % samples was not determined. Analysis of adsorbed metals on 15 samples of plastic particles showed that the mass fraction of metals varies depending on the type of plastic, and polystyrene samples have the highest affinity for the analysed metals, followed by polypropylene and low-density polyethylene samples. Zinc has 7 times higher affinity for low-density polyethylene samples compared to the copper, lead and cadmium. Polypropylene samples have 30 times higher affinity for lead than low-density polyethylene samples, while cadmium has similar values as in low-density polyethylene. Polystyrene samples have the highest affinity for zinc, 21 times higher than low-density polyethylene samples, and the affinity for cadmium is 6 times lower than low-density polyethylene and polypropylene samples. The analysed metals may be present in plastic samples from their production or they may be adsorbed from the surrounding environment. In the Stupica Mala Bay the surrounding soil and rocks are built of carbonate rocks, which are not usual accumulators of metals or a possible source of metals, therefore, the metals are probably originating either from plastic particles or are adsorbed from the seawater.