Regulatory agencies around the world, like other transplanted institutions, might look very similar if one analyzes solely their institutional design. However, there are considerable differences in how they operate in practice. This article shows some of these differences in the Brazilian context. The institutional reforms that took place in Brazil in the mid-1990s created independent regulatory agencies (IRAs) with institutional features that largely resemble the features of US IRAs. However, in contrast to the United States, Brazil has one of the strongest presidencies in the world. Due to the peculiarities of Presidential systems in Latin America in general and Brazil in particular, the theory of congressional dominance that is largely used in the US fails to capture the reality of Brazilian IRAs. This article proposes a theory of presidential dominance to describe that Brazilian reality, and discusses the normative consequences of this presidential control over IRAs from a constitutional perspective.