Studies were carried out to determine counts of TVC 20^oC, TVC 37^oC, TC, FC, FS and Clustridium perfringens in bottom sediments of the Czarna Hancza River, from about 1 cm layer, at 10 stations located in Suwalki region (stations 1 and 2), in the villages Sobolewo (stations 3 and 4), the old river bed of the Czarna Hancza and its intlow to Lake Wigry (stations 5 and 6), and in the villages Czerwony Folwark, Mackowa Ruda, Buda Ruska and Wysoki Most (stations 7-10) east of Lake Wigry. Bottom sediments from stations 1-4 and 7-l0 were mostly sandy, while at stations 5 and 6 they dominated by silty clay. Studies were carried out in 1995 and 1996, at monthly intervals with the exception of winter. Water was examined at the same time. All groups of indicatory bacteria were l00-1000 times more numerous in the bottom sediments than in water. They were usually least numerous in sandy bottom sediments, especially in the villages Buda Ruska and Wysoki Most (stations 9 and 10), and the highest in silty clay sediments in the region of the old Czarna Hancza bed and its inflow to Lake Wigry (stations 5 and 6). Minimal and maximal counts of indicatory bacteria were noted in different months upon particular sampling stations. Only sometimes curves of their numbers corresponded to the respective curves of bacteria counts in water. It is suggested that sanitary and bacteriological studies of water should be supplemented by respective studies of the surface layer of bottom sediments.