Looking at the current state in which Ukraine found itself due to the Russian-Ukrainian war, many questions arise regarding the possibility of estimating demographic losses resulting from this war. A study of the demographic losses of the Western Balkan countries during the most recent wars in this region is a useful preparation for approbation of a methodological basis for future calculations. Therefore, it is currently relevant to study the specifics of the use of general methodological approaches for determining losses under the conditions of a specific social disaster; to assess the demographic losses of the republics of the former Yugoslavia resulting from the Balkan wars, taking into account the specifics of the course of the crisis and the available information base; to determine the possibility of applying the used approaches to the assessment of demographic losses resulting from the Russian-Ukrainian war. The purpose of the article is an attempt to estimate the demographic losses of the republics of the former Yugoslavia resulting from the Balkan wars. The tasks are the analysis of available data and research on demographic losses and obtaining authors’ own assessment of them. The scientific novelty is the generalized information from various sources and the study of the specifics of its formation, the authors’ assessment of the excess mortality and the birth deficit in some republics of the former Yugoslavia. For the purposes of the analysis, the authors provided a chronology of events in the Western Balkans of the late 20th and early 21st centuries and identified sources of information on losses for each former Yugoslav republic. However, despite the fact that many sources can be found in open access, they differ in the diversity of data, calculation methodology, and completeness of presentation. The article presents generalized information on the number of dead as a result of military conflicts based on several analytical sites. The authors defined two approaches, according to which demographic losses can be calculated: the first is the assessment of direct and indirect losses; the second is the use of the demographic balance equation, when excess mortality and birth deficit are estimated. In all the resources cited in the article, the determination of losses is carried out according to the first approach, the authors of the article made an attempt to estimate demographic losses according to the second approach. Using this approach, based on Eurostat data, it was possible to determine losses for only three countries: Serbia, Slovenia, and Croatia. For two regions, Eurostat does not provide demographic data for the years of active military operations: for Bosnia and Herzegovina for 1992—1995, for Kosovo for 1998—2001. In Macedonia, the number of casualties was small, which makes it impractical to build a hypothetical model, while Montenegro managed to avoid war altogether. So, both approaches have one common problem — the lack of a reliable information base. However, differences in loss estimates between the two approaches are natural due to the use of different methodological tools. Nevertheless, the magnitude and causes of large differences require additional research. It should be noted that there are quite a lot of estimates of direct losses, but at the time of the study, the authors were not aware of attempts to estimate excess mortality in individual republics of the former Yugoslavia. The obtained estimates require critical analysis and, if necessary, adjustments. The direction is the reconstruction (or clarification) of demographic dynamics (especially for Bosnia and Herzegovina) taking into account long-term demographic trends.