This paper presents the results of analysis of samples of river water and bottom sediments for PAH and PCB content using previously developed analytical procedures. Conclusions are drawn as to the form and main places of occurrence of the above analytes in the various elements of the river ecosystem (water phase, suspension, bottom sediments). The dependencies which were found between the PAH and PCB concentration in these three phases of the ecosystem suggest that: · PAHs are almost entirely adsorbed on the suspension and their transport in river water occurs mainly with the suspended matter. · PCBs are adsorbed to a lesser degree on the particles of suspended matter, which means that their transport in the river takes place both with the aqueous phase and with the suspended matter. · PAHs accumulate in bottom sediments to a much greater extent than PCBs.