This paper analyzed the adaptation of the population of the Republic of Croatia to the euro, both in theoretical and research form. The manner of functioning of the monetary union and the procedures that must be completed to enter the Union are defined. The process of introducing the euro in Croatia as well as in other countries was analyzed. In addition, the potential advantages and disadvantages of the introduction of the euro were investigated. Finally, the degree of adaptation of the population to the new currency was investigated using a questionnaire. It was concluded that the eurozone had a positive effect on the economies of all member states, so it is considered that the accession of the Republic of Croatia was of immeasurable importance. The results of the survey questionnaire showed that citizens mostly have negative attitudes about the introduction of the euro and that they are not sufficiently informed about the potential benefits of the introduction of the euro. Citizens consider the main disadvantage to be the increase in prices and the decrease in the standard of living, while they didn’t recognize benefits such as the elimination of market risk. The conclusion of the survey questionnaire is that the citizens didn’t adequately adapt to the new currency and that more information and a potentially longer transitional period were needed.