The aim of this research was to evaluate the state of public finance of the 12 new Member States of the EU. It showed that the state of public finance in these countries is generally the effect of conscious state fiscal policies. It means that the EU has not created any effective legal instrument which could stabilise public finance. The only exception was a two-year period of the ERM II system, in which the fiscal convergence criteria were observed. The fiscal rule in the Polish constitution also proved to be a very good solution, worth popularising. Seeking legal instruments which could effectively discipline EU Member States’ public finance should have preceded the creation of the Eurozone. The reality showed that without effective budget policy rules the monetary union was led to a serious crisis, which might bring the Eurozone to its end.