||This paper deals with the question whether is entry of the Czech Republic into the European Monetary Union proper from the view of formal convergence criteria and from the view of Optimum Currency Area theory. The first part attents to the short summary of development of EMU and fulfillment of the Maastricht criteria by the Czech Republic. The next chapter represents the development of the Optimum Currency Area theory and gives theoretical background for the main part of this paper, which deals with the issue of the synchronisation of the Czech Republic and members of the Eurozone. This synchronisation is evaluated by the means of correlation coefficients between cyclical parts of GDP and industrial production and their development in time. For the others indicators are considered the synchronisation of supply and demand shocks and the structural synchronisation. The last chapter deals with the mechanisms, which could partly substitute the function of the monetary policy, which would Czech Republic lost in the case of entry into the Eurozone.