Cohesion policy aims to reduce the differences between the Member States of the European Union that is the disparities in the development levels between their regions. European Structural and Investment Funds are used for the implementation of cohesion policy, where funds contribute to achieve different thematic objectives and the goals of the strategy Europe 2020. In order to reach defined goals, Member States are obliged to determine their strategic directions and own development priorities in operational programmes in line with Partnership Agreement with the European Commission. The aim of this final thesis is to present the process of evaluation and to specify the importance of monitoring and evaluation of the European Union cohesion policy. It is important to observe the outputs and results on time to implement necessary changes. After describing the main characteristics, the implementation of the cohesion policy and programming are presented in more detail. The role of evaluation, ex-ante, on-going and ex-post evaluations are analysed in separate chapter as well as the results of the evaluation with the changes in the last programming period. The results imply on the positive effects of the cohesion policy, but also determine problems in its implementation, confirm the complexity of the evaluation process as well as the need for evidence-based improvements in the creation of the cohesion policy for the future programming period.