The aim of the article is to assess the impact of the euro adoption on the inflation level in the countries of Central and Eastern Europe, i.e. Slovenia, Slovakia, Estonia, Latvia and Lithuania. The hypothesis was adopted that the average price level increase - within the framework of the inflation targeting – is a fixed element of the monetary policy of all central banks, including the European Central Bank. If, after the introduction of a single currency, the rate of inflation is close to the inflation target, then the common monetary policy brings positive effects, and the excessive price increase is only an illusion. As a result of the review of the literature, as well as the analysis of statistical data, it was found that in some of the surveyed countries (Estonia and Slovenia), in the first years after the adoption of the single currency, the price rose above the ECB inflation target, however, this result cannot be attributed solely to the introduction of the single currency (euro). The occurring level of inflation, which is contained in the inflation target of the central bank is acceptable, because its impact on the conomy is positive. The discrepancy between perceived infl ation and its actual level in the new euro area member states may also result from the experience of countries in which – as a result of the price rounding effects – there was an increase in the prices of some consumer goods.