International climate policy is increasingly characterised by the growing involvement of developing countries. In addition to a stronger willingness to participate in global mitigation efforts, there are many examples of domestic mitigation programmes. For example, in 2009 Brazil made a substantial voluntary commitment to reduce its emissions. This paper discusses the dynamics behind the change in Brazil’s position, focusing on the effects of international influences. In conjunction with important domestic changes, a set of interacting influences through a variety of pathways both changed preferences among important interest groups in the Brazilian society towards favouring some kind of commitments and helped to change the structure of government fora and decision-making rules in a way that empowered reform-minded ministries. It is argued that this perspective is increasingly relevant for understanding the influence of external actors on climate change politics in developing countries.