The European Economic Community was founded in 1957. European integration and the creation of a common market begin. The problem of the single market was the large number of currencies in circulation. In 1992, the Maastricht Treaty decided that Europe would have a single, stable and strong currency for the 21st century. On 1 January 2002, euro banknotes and coins entered into circulation. Since then, the number of countries in the euro area has been growing and enlargement of the euro area is still ongoing. The weaknesses of the single currency came to light during the 2008 global crisis. Today, there is a new framework for EU economic governance - implementing rules to help eurozone countries fight to recover and avoid similar problems in the future. The paper presents the course of strategies for the introduction of the euro in selected countries since their accession to the European Union, in the face of the world crisis and today. An analysis has been made of the situation in each country in terms of the preparation phase of the introduction of the euro, the obstacles they face, the planned years of introduction of the euro, and how policies can be adjusted to make this step a reality. The paper analyzes the positive and negative effects of the introduction of the euro on the examples of Poland, the Czech Republic, Hungary and Croatia.