In this paper the reform process of European procedural competition law shall be analyzed from a law and economics perspective, starting with the famous Regulation 17 and ending with Regulation 1/2003 which will enter into force in May 2004 (and will be immediately applicable in the new Member States). The focus lies on the system switch from a centralized authorization system to a system of decentralized ex post control with a broader scope for private court actions. It will be analyzed in how far the system switch affects overall efficiency. Finally, it shall be examined in how far specific provisions of Regulation 1/2003 can contribute to enhancing the efficiency of the procedural law.