The aim of the paper is to analyse a level of compliance of the euro area with the OCA criteria. To reach the aim set, the authors have used methods of theoretical, statistical, mathematical and graphical analysis, comparison and induction methods, and the analysis of secondary data. As a result of the performed analysis, it has been concluded that the euro area is not optimal, and the stable functionality of the system under the existing risks and problems is not possible. Therefore, as additional criteria for the estimation of the currency area optimality it is possible to apply the efficiency and innovation rate in the EMU member states and the diversification indicators of export partners.