Currently, thirteen of the European Union’s 27 Member States form the euro area. Therefore, Denmark and the United Kingdom have a special “opt-out” status and Sweden does not fulfil all the required criteria. For the 2004 and 2007 entrants, joining the Economic and Monetary Union (EMU) is an ambitious objective. So far only Slovenia achieved this goal, on the 1st of January 2007. Cyprus, Estonia, Latvia, Lithuania, Malta, Slovakia already entered the “waiting room” for the EMU while the three largest new member States – Czech Republic, Hungary and Poland – remained outside the ERM II. Bulgaria and Romania, which joined the EU in 2007, are expected to join ERM II and, eventually, the EMU as soon as possible. This paper intends to provide an analysis of the current state and the prospects of the “enlargement” of the euro zone and to discuss some of the issues related.