The ASEAN Economic Ministers unveiled the ASEAN Regional Guidelines on Competition Policy on 24 August 2010. This is a non-binding document covering all key issues relating to competition law and policy. This article provides a comparative study of the regional harmonization of competition law and policy among the EU, NAFTA, MERCOSUR, CAN, and ASEAN, with a focus on ASEAN. In contrast to the “hard law” approach of the EU, NAFTA, MERCOSUR, and CAN, ASEAN has opted for a “soft law” approach because it is constrained by (1) the traditional “ASEAN Way”; (2) the diversity in economic conditions and competition regimes among its members; and (3) the lack of a supranational body to enforce common competition rules, or, at least, a mechanism for dispute resolution. The author concludes that this modest step which ASEAN has taken in the regional harmonization of competition law and policy is appropriate for the time being.