The main objective with the thesis was to analyze institutional change in the European Union pre-and-post financial debt crisis, with particular focus on the roles of the Parliament, the Commission, the Council as well as the Court of Justice. To attain the objective, the thesis intended to answer the subsequent queries; (i) what notable institutional changes were brought in the European Union pre-and-post financial debt crisis; (ii) what role did the Parliament, the Commission, the Council and the Court of Justice play pre-and-post financial debt crisis; were their roles enhanced by the financial debt crisis? In order to attain the objective, the thesis utilized an institutional analysis and development framework. This theoretical framework relied on a qualitative content analysis.  The results of the thesis exhibit that the European Union’s progression route was not free from crises. With the Union’s expansion, more decisions ought to be taken by the four institutional bodies. The role of the European institutional bodies resulted in various institutional changes with the establishment of the Treaty of Lisbon; from having a normative power to encompass an executive one. The Treaty of Lisbon also changed the decisionmaking procedure to an ordinary legislative procedure. Apropos decision-making, the Treaty of Lisbon also enhanced the Council and the Parliament’s role pre-financial debt crisis by making the Parliament and Council equal in the new co-decision procedure. The role of the Council has been dynamic since its formation, while the role of the three other institutions could somewhat vary throughout the pre-financial debt crisis. With regards to institutional change after the financial debt crisis, the results reveal that institutional changes occurred mainly in economic and fiscal policies, for instance strengthening the EMU with the intergovernmental Treaty on Stability and Coordination and Governance. Whilst the Treaty of Lisbon brought more supranationalism in the European Union, the period after the financial debt crisis rather celebrated intergovernmentalism in the Union. The role of the Council was dynamic even post-financial debt crisis, decreasing the role of the Commission in the agenda setting. However, with the introduction of the Six-Pack and the Banking Union, the Commission and the Parliament’s role became evidently enhanced, whilst the Court of Justice, did not play a key role in the financial debt crisis.