This article addresses the problem of the EP’s role in the process of multi-level governance illustrated with the example of EU expansion policy through the accession of the West Balkan states. As an effect of the European integration process, resulting in the transfer of decision-making competences from the state level to the transnational level, nation-states have lost their monopolistic position in the European decision-making process. This has enabled the formation of multi-level political system within the EU. Within the system, there is a multi-level governance model, with the EP as its crucial element. This article reveals an important role of the EP as a transnational decision-making centre, which with its specific competences (giving consent to the accession of a country to the EU, giving consent to sign international agreements crucial for the integration process, budget rights, co-decisions on the form of the EU law with an ordinary law making procedure) considerably forms the policy of the EU in relation to the Balkan countries. The explanation of the policy’s functioning and its outcomes are based on the concept of multi-level governance, which is analyzed herein in depth.