The aim of this paper was to build an empirical model for evaluating the comparative analysis of the impact of the real exchange rate on economic growth over the period 2000-2021 for selected European post-transition countries: Croatia, Hungary and Slovenia. Previous research and empirical evidence do not provide a universal picture of the impact of the real exchange rate on economic growth and insights into the real exchange rate as a variable of economic policy. After explaining the concept of the real exchange rate, how it is measured and its impact on economic growth, the paper reviews previous research, on the basis of which the variables used in this study were selected. The dependent variable in the model is economic growth, measured by GDP per capita. The main independent variable is the RER (index), and the other independent (control) variables are: Savings as % of GDP, Government Expenditure as % of GDP, FDI inflows as % of GDP, Private Sector Credit as % of GDP and Rule of Law. In the SPSS programme, correlation analysis (Pearson's correlation coefficient) was used to examine the relationship between GDP per capita and six independent variables, while the dependence of GDP per capita on independent variables was analysed for selected European countries after the transition using a multiple linear regression model. Based on the correlation and regression analysis, the decision to accept or reject the above hypotheses was made for each selected European country after the transition. The results of the econometric analysis show that the first hypothesis (the real exchange rate influences economic growth in such a way that an overvalued real exchange rate negatively influences economic growth and an undervalued real exchange rate positively influences economic growth on the example of selected European post-transition countries) cannot be accepted in the model of the Republic of Croatia, while the above hypothesis is accepted in the model of Hungary and Slovenia. The second hypothesis (An appreciation of the real exchange rate in a situation with higher economic growth, higher savings rate and lower government spending leads to a lower impact of the REER on economic growth) cannot be accepted in any model. The results of the paper are consistent with the review of previous research as well as the theoretical framework of the relationship between the variables. The importance of the RER as a measure of a country's competitiveness and development in the situation of a fixed exchange rate and the EU common currency will become more important. It is important to be able to determine the factors or determinants of the influence on the RER.