This article addresses the relevance of ne bis in idem, that is, prohibition on double jeopardy, six years after Regulation 1/2003 introduced a major reform of the enforcement system of European Union (EU) competition law. In particular, it considers whether and to what extent parallel action by the European Commission and/or National Competition Authorities (NCAs) is still possible under the modernized system. This article calls for the EU Courts to review the application of the principle of ne bis in idem not only to reflect the changes brought about by Regulation 1/2003 but also to give full effectiveness to the Charter of Fundamental Rights of the European Union, which the Commission and the European Courts are now legally bound to respect, following the entry into force of the Lisbon Treaty.