The article discusses the institutional aspects of the activity of the European Central Bank. It presents the challenges to the institution regarding the anticipated adoption of the single European currency by subsequent EU Member States. The arguments of the potential negative effects of the quantitative advantage of small, rapidly developing countries after the enlargement of the euro zone have been critically analysed. The draft reform of the decision-making processes in the ECB Council and its potential alternatives have also been discussed. It is assessed that irrespective of some drawbacks, the accepted project enables smooth functioning of the Economic and Monetary Union.