In this paper, the results of the analyses of selected chemical water quality parameters and taxonomic composition of macroinvcrtcbratcs of the Liwiec River and its chosen tributaries (central-eastern Poland) arc presented. Chemical and biological water quality assessment was performed, and four biotic indices were tested: Belgian BBi, French IBGN, British BMWP/OQR, and biotic index BMWP-PL developed for Polish rivers. Correlations between the values of the latter and chemical water parameters show that BMWP-PL is a useful tool for the assessment ofwater quality of lowland rivers in Poland (similar to the Liwiec).