In light of the growing importance fundamental rights have acquired in competition enforcement and of the ramifications of the Lisbon Treaty (EU accession to the ECHR, binding Charter), this thesis assesses two paramount concerns: whether the current level of fundamental rights protection in cartel enforcement falls within the accepted ECHR standards  and how the often conflicting objectives of effectiveness and adequate protection of fundamental rights could optimally be achieved. Normative answers to both questions are given following a thorough analysis of EU institutional, substantive and procedural law rules. Accordingly, the thesis first provides a theoretical analysis of the legal framework of fundamental rights protection identifying the pertinent rights and legal nature of competition proceedings under EU and ECHR law. It then tackles the long-standing debate of the compatibility of the EU enforcement system with the ECHR’s due process institutional requirements. Thereafter, a cartel-specific analysis is conducted juxtaposing the increased investigatory powers vested in competition authorities with the privilege against self-incrimination and right to privacy. The interaction between the substantive rules of legal qualification of cartels and the “fair trial” probatory requirements is then examined, as to illustrate the degree of use of presumptions in EU practice. These will then be weighed against the Article 6 ECHR guarantees pertaining to the presumption of innocence in the form of an adequate set of standard/burden of proof and evidence admissibility rules. The thesis proceeds with a review of the rules of attribution of liability and fining, attempting to reconcile “effective deterrence” with the principles of legality, non-retroactivity, presumption of innocence and ne bis in idem. Having appraised the entire spectrum of enforcement components with a fundamental rights dimension, general conclusions are drawn on the status of compatibility with the ECHR and on the necessity of introducing further reforms enhancing the overall effectiveness and legitimacy of the system.