Regulatory Impact Assessments (RIAs) are being diffused progressively throughout the world following the recommendations of international organizations. Research has shown that the diffusion of RIA has not produced convergence in actual practices, particularly in developing countries, due to political forces at work in domestic contexts or the available organizational capacities. The Organisation for Economic Co-operation and Development (OECD) has recently recommended that the Brazilian federal government adopt RIA. This article evaluates how contextual variables, specifically political and organizational ones, influence RIA adoption in Brazil. It is based on field research consisting of semi-structured interviews with the main stakeholders of the Brazilian regulatory framework. The research explored RIA concept familiarity among stakeholders, the bureaucratic context, the policy process, pivotal stakeholders' standpoints in adopting RIA, and available organizational capacities. Contrary to previous studies in developing countries, the research reveals that strong organizational capacities are not a sufficient factor for successful diffusion of RIA, because political variables can influence divergence among agencies in future RIA practices.