One can think that the creation of the euro area and its expected enlargement eastwards to new members may have deep consequences upon regional/cohesion policy. And that comes unsurprisingly, since the first authors to theorise about monetary unification have debated the possible deterioration of regional economies or the changing nature of national problems into regional ones, namely in the case of small, open economies. I remind that “region ” is a key word/concept in the seminal paper by Mundell (1961) on “optimum currency areas”. My conclusion is that those costs have been exaggerated. What can we learn from the brief experience of the final stage of Economic and Monetary Union or even conclude, if only tentatively, and what pieces of advice will be more appropriate to newcomers as to their thoughts to the consideration of joining the euro area? The general conclusion is that, since our EMU is very young, the required data to proceed with empirical analyses are not yet available. However, that does not prevent us to examine some issues in need of further attention. i) First Draft. ii) This paper is delivered in a personal capacity. Its views are not necessarily shared by the Portuguese Authorities.