The objective of this investigation was to evaluate the usefulness of the artificial substrate sampler in collecting macroinvertebrates for water quality assessment of Polish lowland rivers. This paper presents the results of a comparative study between two different sampling techniques, i.e. nettings filled with brick as artificial substrates and handnet sampling. The validity of applying the biotic index method is also demonstrated. The Belgian Biotic Index (BBI) method and the lower Nysa Kłodzka river were chosen for study. Macroinvertebrates were collected seasonally at five sampling sites. Although some invertebrate taxa revealed a specific preference for one of the two tested sampling substrates, the artificial substrates and handnet samples had a similar fauna composition. BBI scores were rather insensitive to the different sampling methods used during the study. Taking into account all sampling seasons, 60% of the BBI values for the two sampling techniques were the same and nearly 27% scored one unit lower or higher. This has led to the conclusion that water quality changes of the river ecosystem in Poland can be demonstrated by means of the analyses of macroinvertebrates colonizing artificial substrates.