Within the European Union, one of the most developed economic association in the world, there are large regional disparities. Inequalities between regions and Member States have a very negative impact on economic, social and territorial cohesion. Reducing regional disparities is essential for the progress of the EU and to achieve competitiveness in the global market. Cohesion (regional) policy was created precisely in order to reduce regional differences among the EU. It is based on the financial solidarity principle, part of funds from the EU budget are directed to disadvantaged regions or States. EU created special structural and cohesion investment funds, defined by thematic areas whose development is encouraged. The main framework for the implementation of cohesion policy is NUTS classification. The NUTS classification is hierarchical system that divides the territory of the Member States on the three statistical levels. Based on NUTS divisions the EU define the regional problems of the Union and diverted funds in the less developed areas. Cohesion policy is changed a lot from its beginning. A series of new reforms and financial perspectives are proof to that. Every new financial perspective presented a new financial framework, new budgetary period and new objectives of the cohesion policy. All financial perspective had a positive impact on the convergence process, in greater or lesser extent. However, the EU still recorded large regional disparities. Regions in the Union range from extreme wealth to extreme poverty, sometimes on the same national territory. Despite the positive impact of cohesion policy on the convergence, large disparities between regions and Member States continue to exist. The youngest EU member states are also the poorest, despite the high percentage of growth in economic indicators after the EU accession.