Sediment samples were taken in 11 measuring points of the Biebrza River and determined the contents of six metals (Cu, Cr, Co, Ni, Cd and Zn). Arithmetic mean, median and standard deviation were calculated. The sources of heavy metals in bottom sediments are: pollutants of fieldsand meadows (admixtures of plant protection products and fertilizers), discharges of domestic sewage and municipal from local wastewater treatment plants, wastewater di-scharges from rural buildings and pollutions of anthropogenic origin. Research of pollution of bottom sediments with heavy metals are needed tool for monitoring the aquatic environ-ment. Continuous monitoring metal content of the sediments will counteract the effects of the threat of biological life in the water reservoir, which may occur in the case of notorious exceeded permissible content of harmful substances.