This study investigates the relationship between net migration and economic development in European countries, focusing on the EU-27 member states, Switzerland, and Ukraine. Using correlation-regression analysis based on data from Eurostat and the State Statistics Service of Ukraine for the period 2014-2021, the study finds a positive and significant correlation between net migration and GDP. The analysis shows that an increase in net migration by 1% can lead to a 1.93 million euro increase in GDP in Poland. Due to the Russian-Ukrainian war, net migration from Ukraine to Poland has significantly increased, potentially boosting Poland's GDP by 0.08% or 529.54 million euros in 2023. The study also highlights the importance of migration, particularly labor migration, in economic growth, with Poland being an attractive destination due to its simpler immigration process, ease of language learning, and higher living standards compared to neighboring countries. The findings suggest that migration can be a crucial factor in economic development, but the impact varies across different countries.This study investigates the relationship between net migration and economic development in European countries, focusing on the EU-27 member states, Switzerland, and Ukraine. Using correlation-regression analysis based on data from Eurostat and the State Statistics Service of Ukraine for the period 2014-2021, the study finds a positive and significant correlation between net migration and GDP. The analysis shows that an increase in net migration by 1% can lead to a 1.93 million euro increase in GDP in Poland. Due to the Russian-Ukrainian war, net migration from Ukraine to Poland has significantly increased, potentially boosting Poland's GDP by 0.08% or 529.54 million euros in 2023. The study also highlights the importance of migration, particularly labor migration, in economic growth, with Poland being an attractive destination due to its simpler immigration process, ease of language learning, and higher living standards compared to neighboring countries. The findings suggest that migration can be a crucial factor in economic development, but the impact varies across different countries.