The paper probes the notions of an “optimum currency area” (OCA) and “business cycle synchronization” in the context of convergence within the European Monetary Union (EMU). Analyzing the latest literature in this area, the author concludes that most of the measures currently used and promoted ignore the key advantages and disadvantages of an optimum currency area. At the same time, the paper attempts to apply a common tool of gravity equation to test the possible impact of the EMU on trade patterns among EU member states. By implementing a traditional notion of gravity equation, the author demonstrates that, as far as international trade is concerned, it is possible to move trade flows from non-EMU countries to those using the single European currency.