The purpose of this paper is to research on the Central and Eastern European countries’ (CEECs) economic development after joining the European Union (EU). Moreover, this study highlights the key policies of economic integration into the EU and integration is a success story for the CEE countries. This paper also describes the key indicators and tools of the development model adopted by the CEE countries as a member of the EU. This study covers the period from 2004 to 2021. The objective of this study is to relate to the EU’s economic and trade policies, and how they brought the development to the region after the successful integration. To what extent, the CEE countries could develop their economic position in comparison to the other EU member countries. The research used empirical and comparative analysis methods to search the economic growth and regional development. Through this method, the research answers the questions and tests the hypothesis. The study concludes that the economic integration of the CEECs into the EU is successful. As a result, the development of this region has been accelerated and the EU’s economic policies have successfully been implemented in many countries. Finally, The EU’s economic policy has changed the dynamics of regions’ development and shaped the stronger trade and common market among the member states. The EU’s integration has impacted the gradual economic growth across the CEE countries.