The main goal of the research was the assessment of the impact of industrial and municipal wastewater discharges on aquatic ecosystems of Kłodnica river. The conducted studies were based on bioindication methods. Within the ecotoxicological analyses the biotest battery was used. The scope of the analysis included determination of influence of anthropogenic pollutants present in Kłodnica river on growth of hydroponic plant (Lemna minor). Also the acute toxicity test using crustacean (Daphnia magna) and bioluminescence bacteria (Vibrio fischeri) were performed. Toxic effects were observed only during the phytotoxicity test in which the plant growth inhibition level exceed respectively 25% and 50%. During the research no other toxic effects of analysed river water samples was observed. The analysed samples did not affect the inhibition of metabolic process of bacteria Vibrio fischerii, on the contrary, the water high salinity stimulate it. During the MICROTOX® test the phenomenon of hormesis was observed.