EN
In the article the results are presented of the latest censuses carried out in Byelorussia in 1999, and in Lithuania and the Ukraine in 2001. The basic task of the study was to determine how big the Polish population was. The Byelorussian census showed 396 thousand, the Lithuanian one – 235 thousand, and the Ukrainian one – 144.1 thousand Poles. Altogether in the three mentioned countries bordering upon Poland the official census data showed 775.1 thousand Poles. This was 98.1 thousand fewer than the previous census carried out in the Soviet period (1989) showed. The author tries to explain the causes of this state of things. Earlier assessments done by Polish researchers showed that the data from Soviet censuses lowered the number of Poles and it was expected that the censuses carried out under new circumstances would show a considerably bigger Polish population. The results of these censuses did not confirm these research hypotheses. The constant decrease in the number of Poles in Byelorussia, Lithuania and the Ukraine results from assimilation processes that have been stimulated by social and economic changes. In the next part of the article the author tried to present the distribution of the Polish population according to the administrative units of the province or district level. A special attention was paid to the Vilnius district in Lithuania and the Grodno province in Byelorussia. In both these areas the Polish population tends to concentrate. On the other hand, the processes of atrophy of the Polish population go on in the Ukraine. This is due to the diffusion of the Polish population and its gradual sinking into the Ukrainian community.