The purpose of this article is to provide a comparative analysis of the transnational legal processes that Brazil and Argentina underwent to address money laundering. The article discusses the interaction between the Financial Action Task Force (FATF) norms and a number of changes both countries have experienced in the last decade. The comparison focuses on the three central pillars of the anti-money laundering order (AMLO): criminalization, administrative obligations imposed on the financial sectors, and the creation of a financial intelligence unit. Building from the analytical framework developed by Shaffer (2011), the evidence gathered in this study illustrates different dimensions of state change and highlights the main challenges to assess the effectiveness (output legitimacy) of transnational legal orders empirically.