The paper addresses the most recent amendment of the Italian Constitution, enacted in April 2012, and the budget constraints deriving from it. The analysis focuses first on the complex regulatory framework, whose elements now are both of national and supranational sources. It aims to make clear the difference between the balanced budget rule, whose introduction has been announced by the heading of Constitutional Law n. 1/2012, and the real content of the amendment, always referring to budget plans in terms of equilibrium. Then, the article deals with the threefold approach embraced by the text of the Constitution and by the law that has implemented and specified it. In fact, the goal of equilibrium is now imposed not only on the general government —as European law already required— but also on the State budget plan and on local government ones. Moreover, while the latter are expected to break even notwithstanding the economic conditions, the State and general government have to reach equilibrium in structural terms, which allows for the production of limited deficits when economic growth turns out to be negative. This shows the inconsistency between the constitutional provisions previously in force, which where neutral with respect to the underlying key issue of economic interventionism, and the current ones, implicitly validating the economic assumptions on which European budget rules are grounded. Second, the article examines the effects of the decision to establish the principle directly into the fundamental law. Arising from the same cultural background in which both the overload thesis and the technocratic drift of European institutions have developed, this choice inevitably affects the very core of constitutional law. In the first place, the amendment transformed external constraints into constitutional rules, resulting in a further transfer of sovereignty from Italy to the EU. At the same time, it strengthened European rules, charging the Constitutional Court with a judicial review that once was not even possible. But above all, the principle of equilibrium seems now to prejudice the fragile balance between financial stability and the protection of citizens’ social rights