The concentration of three heavy metals in the tissues of the toad Bufo bufo, living near the area of the Mochovce, Slovakia. The liver contained significantly higher amounts of copper (males: 570.83±37.33 μg/g dry weight, females: 90.75±2.45 μg/g dry weight), the kidney contained higher amounts of cadmium (males: 15.42±2.68 μg/g, females: 15.16±0.93 μg/g dry weight). The high concentration of zinc was detected in kidney (males: 148.18±37.81 μg/g, females: 126.24±14.16 μg/g dry weight). Such concentrations of copper, cadmium and zinc, corresponding to the highly polluted areas, were detected. Toads were during matting period and they were migrated to the wet areas over the stream. The main sources of the stream pollution seem to be fertilizers containing heavy metals as trace elements, pesticides with a heavy metal in their formula, industries and peoples discharge their effluents into this stream.