Within the management of capital flows, some emerging economies have been facing economic policy dilemmas after the global financial crisis, related to financial instrument operations, in a context of abundant liquidity in the advanced economies. However, neither the academic literature nor the financial institutions have paid sufficient attention to foreign currency (FX) derivatives regulation in emerging economies. This paper analyses the measures adopted by Brazil and the Republic of Korea. We find, first, that the breadth of regulation concerning FX derivatives operations depends on the actors involved and the type of contract used. Second, effective domestic institutions are needed to formulate and implement regulations. Third, countries should not limit their policy space through multilateral or bilateral agreements, and leave space for domestic financial regulation.