Croatia is on the verge of political decision to start the process of introducing the euro and the introduction of the euro is its obligation under the EU Accession Treaty. However, the process of introducing the euro is, in its initial part, optional. Namely, Member States are free to choose the time to apply for entry into the European Exchange Rate Mechanism II, which is also the previous stage for the approval of the introduction of the euro. This option also creates the wrong impression that an EU member state can refuse the introduction of the euro, by its free will, expressed in a referendum or a legislative body decision. This specialist graduate thesis deals with the benefits and costs (advantages and disadvantages) of introducing the euro into Croatia, but after exploring the historical economic and political context of the creation of the monetary union. Monetary arrangements that preceded the Eurozone, the “road to Maastricht”, the creation of the European Union and the Monetary Union within its framework were explored in the thesis. This paper provides a brief explanation of the main institutions of the Eurozone. The paper also deals with aspects of the theory of the optimal currency area, which is also the "spiritual father" of the creation of modern monetary unions. The paper describes the causes of the 2008 Global Crisis as well as the 2009 Eurozone crisis. The individual experiences of Finland, Greece and Slovenia in the Eurozone before and after its crisis are depicted, as well. The paper presents an overview of new institutions and anti-crisis mechanisms in the Eurozone, arising after the Eurozone crisis.