The article covers matters of improving measurement on emigration from Belarus. The author views the current role of external migration as a major component of formation of the population in the Republic of Belarus. The effectiveness of the country socio-economic development programs depends, according to the author, on adequate measures for evaluating the phenomenon in question. The article gives a detailed description of national migration statistics, which, as in many countries, underestimates the number of emigrants, and considers the possibilities of the so-called «mirror» statistics (statistics from countries where Belarusian residents emigrate to) in obtaining real information on the size of emigration from Belarus.After the introduction, the author analyses some of the most important publications on the subject under discussion, concludes the current state of current statistics and population censuses. The article contains the rationale for choosing foreign countries whose data are used as «mirror» statistics necessary for a more realistic estimation of emigration processes and comments on the geography of migration flows from Belarus. The author assesses the gap in data from «mirror» statistics and the official Belarusian statistics and gives an opinion on the real trends in migration flows of Belarusian citizens, along with the authors own estimates of the country’s population growth, which differ markedly from official statistics.In the opinion of the author, formulated in the final part of the article, the actual amount of the underestimation is considerably higher than can be assumed using «mirror» statistics, because, for example, there is a group of Belarusian citizens in Poland and Russia, that is not reflected in official statistics on migrants. The article therefore proposes to establish a system of information exchange between Belarus and the main countries of emigration, especially Russia and Poland, with which it is difficult to assess the extent of emigration based solely on official data, and to establish regular surveys on emigration.