The emigration of young, working-age population from the Republic of Croatia, especially from Eastern Slavonia, is a current growing trend which can be witnessed daily, and which can already be considered a national disaster, both demographically, as well as economically and socially. This trend is an immediate reason for choosing a bachelor thesis on the topic of: The effect of population emigration on the economy of the Republic of Croatia. By reviewing literature which discusses this topic and comparing data, this paper strives to determine the current trends and explain their significance to the economy of the Republic of Croatia. The thesis first explains the key terms for this topic: population, demographics and migration. In order to provide additional insight into the topic, the following terms closely related to this issue will also be explained: fertility, birth rate, death rate, emigration, immigration, working population. The thesis continues with explaining demographic changes in Croatia. This part namely explains the primary causes of depopulation and population ageing. According to the data provided by the Croatian Bureau of Statistics, the thesis also provides a comparison of the data from the Census od Population 2001 and Census od Population 2011. Additionally, the thesis reviews the causes of emigration, as well as the influence of population emigration on economic changes, and more precisely, on the labour market and public finances. The overall conclusion of the thesis is that external migration from the Republic of Croatia is extremely high, and will have a strong negative long-term effect on the economy of the Republic of Croatia. Therefore, in order to stop the negative demographic trends, it is necessary to implement urgent and specific measures at the highest national level.