Large corporate groups have dominated Indonesia’s corporate landscape for decades, and are controlled by a relatively small number of elite families. This chapter looks at laws that were introduced after Soeharto’s fall to create a more competitive economy, and establish the KPPU, Indonesia’s competition commission. The chapter begins with an account of the key provisions of the Competition Law, including the rules relating to monopolies, monopsonies, oligopolies, cartels, market share, dominant position, exclusive dealing, and mergers and acquisition. It then provides an assessment of the KPPU’s structure and powers, its performance, and its relations with the government, as well as problems with the enforcement of its decisions. The chapter includes several case studies, including the Donggi-Senoro case.