Changes in numbers and distribution of wintering waterfowl species in Belarus observed in recent decades are analysed. Data on species composition and numbers of wintering waterbirds were collected by means of surveys conducted in 19811998. The total number of wintering species in Belarus increased from 13 to 35 during 19672000 and the number of regularly wintering species did so from one in the 1960s to 13 in the late 1980s. Numbers of wintering waterfowl increased from about 1,000 individuals in 1967 to over 50,000 birds in 1991. Most waterbirds were recorded in southwestern and central Belarus, where winters are milder than in the north of the country. The majority of species and the largest concentrations of wintering birds were recorded on artificial reservoirs polluted by heated waste waters near large industrial centres. It is likely that in Belarus the northernmost ice-free wintering sites were firstly colonised by short-distance late migrants adapted to the environment with low air temperature.