This paper deals with the sanitary conditions of the water and bottom sediments in the Lower Vistula river, between Wyszogrod and Torun. The contamination extent of the water and bottom sediments by easily decomposable organic matter and substances of faecal origin have been indirectly estimated by determining the total number of heterotrophic bacteria (TVC 20degreesC) and the occurrence of the faecal coliform (FC) and faecal streptococci (FS). Examination results enabled a classification of this water as moderately and moderate highly affected by the easily decomposable organic matter and faecal substances. The bottom sediments, however, contained a much greater load of psychrophilic and faecal heterotrophic bacteria, yet they were polluted to a moderate extent. According to bacteriological results the examination site that revealed the greatest extent of easily decomposable organic matter and faecal matter, both in the water and bottom sediments, was the study site near Plock (site II). The least affected sites were those in the Wloclawski Reservoir dam (site III) and near Nieszawa (site IV). The faecal contamination factor (FC:FS ratio), in majority cases being more than 4, indicated that it was human-borne faecal contamination that dominated the area.