Microplastic represents one of the main sources of environmental pollution in all ecosystems, including aquatic ones at global level. This research studied microplastic from water column, sediment and fish of Sava River from three locations. Six (6) water columns, twelve (12) sediment and six (6) fish samples were examined in total. First, organic matter was removed from all samples, then the carbonate component was removed from sediment and water column samples. Subsequently, using density separation method, which was performed for the purposes of this research using the solution of sodium polyhydrate (SPT) with a density of 1.65 g/cm3, microplastic was separated, and all the samples were subjected to visual inspection under a magnifying glass. Identification was performed on FTIR (Fourier-transform infrared spectroscopy) and two types of microplastic were identified: polypropylene (PP) and naylon. The dominant color of the isolated particles was black, but particles of other colors such as blue and red were also present, most of the particles fibrous in shape. In sediment samples, the number of microplastic particles increases downstream from point 1 to point 3 and is highest at point 3. In samples obtained from the suspension of water, the number of particles decreases downstream from point 1 to point 3, while in fish samples the smallest amount of microplastic particles was found at point 2 and the largest at point 3.