In 2013, by joining the European Union and signing the Treaty on European Union, the Republic of Croatia agreed to accept the euro as its currency, i.e. it undertook the obligation to join the European Economic and Monetary Union. Since July 10, the Republic of Croatia has been participating in the European Exchange Rate Mechanism ERM II and is on the verge of introducing the euro as a legal tender. This paper aimed to present the possible consequences of the introduction of the euro in Croatia based on the experiences of selected eurozone members. The entry into the euro area of three newer members has been analysed: Slovenia, Estonia, and Latvia. These countries were chosen based on their similarities with the Republic of Croatia as transitional, small countries with open economies. The research briefly presents the European Union, the eurozone, its institutions, and mechanisms of action. The paper also tackles the aspect of the theory of the optimal currency area and the advantages and disadvantages of the introduction of the Euro in Croatia. From the analysis of the collected data on the observed countries, it is concluded that the benefits of the introduction of the euro will outweigh the costs. The Government of the Republic of Croatia should pay special attention to timely inform the population about the benefits of the Eurozone, and the development of a strategy that would slow down the emigration of the working-age population.