The global upsurge of interest in corruption has led to the proliferation of anti-corruption instruments in international law. Such legal responses to corruption may be usefully divided into three interrelated planes of action: the promulgation of formal international legal instruments by organisations such as the UN and OECD; the work of national bureaucratic agencies cooperating across borders to enforce national anti-corruption laws; and the work of wholly non-governmental organisations such as Transparency International. The difficult task of regulating transnational actors, particularly corporations, requires an understanding of how these planes interact, and which elements would best be strengthened to further the fight against corruption. Furthermore, such regulation must carefully balance questions of efficacy against those of legitimacy. The purpose of this paper is to assess modern regulatory literature, particularly regarding corporate behaviour, and draw from it lessons for the development of the international anti-corruption legal regime.