Behind the term “the Taricco saga” lie two ECJ cases on VAT fraud. In this article, the author analyses these two decisions under the framework of the principles of effectiveness of EU law and primacy and direct effect. The author outlines the important challenge faced by the ECJ because of a possible conflict between the general principles at stake and the impact of ineffective VAT collection on the European Union’s financial interests. These cases also show the disputes that can arise in the area of EU tax law with respect to the adequate level of protection of fundamental rights and principles within the framework of EU multi-level constitutionalism.