Campylobacter isolates were detected in 82.1% of river water samples moderately polluted with organic wastes. In the majority of the samples less than 10 Campylobacter cfu/100 ml were detectable. The presence of waterfowl and the faecal contamination from a poultry-farm resulted in considerable higher Campylobacter contents (greater than 240/100 ml). Correlation studies showed a high correlation coefficient (P less than 0.05) between the number of campylobacters and that of total coliforms. Campylobacter isolates were never found in river water samples of 100 ml of volume with total coliform contents less than 10/ml. Campylobacter contents and the spectrum of serotypes isolated indicate hygienic precautions for drinking water supply from oligotrophic surface waters if the water is distributed without chlorination.