Since 1999 Indonesia has the Law on Anti-Monopoly and Unfair Business Competition (Indonesian Monopoly Law/IML). Anti-Monopoly and Unfair Business Competition Law provides the roles for the Commission to supervise on any unfair business competition. However, there are many strategies prohibited business conducted by business, such as cartel. Cartel is a banned agreement mentioned in Article 11 of Anti-Monopoly Law in Indonesia because gives loses to the consumer and others businesses. The research aims to discuss on the roles of KPPU on disputes settlement of cartel cases in Indonesia. The research method used in this research is Normative Legal Research, by reviewing to some theories, legal principles, Indonesian Law, KPPU and Court Decision in settling the Cartel Cases. The research conducted through library legal research with legal document. The result of research first, KPPU has authority to settle the unfair business cases from the investigation process until the first proceeding. Second, shows that some of cartels cases may be settle through KPPU. While, other cases conducted the legal effort to the General Court and Supreme Court.