European monetary integration was realised through law. The role of law in setting up monetary authorities, legal procedures, instruments and acts necessary for the conduct of the future common monetary policy is undeniable. A number of sovereign countries surrendering monetary sovereignty to adopt a common currency is a completely new phenomenon in history, and so an original experiment. This brought with it a series of legal consequences. Law had to guarantee the result of monetary unification, at the end of a convergence process, and it had to give credibility to the new currency inside the area of circulation and outside of it, on international markets. Its role was essential as any aspect of the future monetary institution, of its powers, competences, instruments, was set by law. There is also another side of the coin: EMU being regulated by European primary law implies that any adjustment or change in its legal framework should be codified amending the previous provisions, unanimously, by means of a new treaty. This makes the system quite rigid in its initial, fundamental decisions, which were basically different in the two distinct fields of economic and of monetary policy. So, in monetary policy, there is a transfer of sovereignty and the creation of an exclusive European competence, in economic policy we see a limitation of national sovereignty and the coordination of national competences. What happens if (or better when) we realize that the two policies are not as separate as they may appear? This is what happened during the Euro-crisis. The contribution provides a critical approach to the European legal framework as well as an overview of the possible reforms.