At the present time, Turkey houses about 500 wetlands, 76 of which have an international importance to some degree and extend over 1.295.456 hectares. These areas are very important for waterfowl as many migration routes intersect over Anatolia. The Ramsar Convention defined wetlands as “areas of marsh, fen, peatland or water, whether natural, artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salty, including areas of marine water to the depths not exceeding six meters at low tide”. Wetlands have values and functions that cannot be compared with those of other ecosystems. This study was conducted “in December 2003” to determine the waterbirds existence within the lakes of Sapanca, Acarlar, Kanlı, Kamış, Gölkent and Poyraz of Sakarya river basin and the Black Sea coastline where the river flows into, in December. In all wetlands, except for Acarlar lake, observations were carried out by point counts method; birds were counted by transect observation method in Acarlar lake because it was a forested wetland. As a result of this counting study, a total of 55877 waterbirds (29 species) belonging to 11 families out of 9 orders were determined. With 32374 individuals, Coot (Fulica atra L. 1758) produced the highest numbers of waterbirds. Red-throated Diver (Gavia stellata (Pont. 1763)), Red-necked Grebe (Podiceps grisegena (Bo. 1783)) and White-headed Duck (Oxyura leucocephala (Scop. 1769)) are the least numbered birds in the region, they were observed very seldom and represented with just an one individual at the study area.