In recent years, the United Nations has taken a lead in advocating public-private partnerships (PPPs), and various UN entities actively seek partnerships and alliances with transnational corporations and other companies. Although there has been a rapid growth of PPPs, relatively little is known about their contribution to basic UN goals associated with inclusive, equitable and sustainable development. In response to this situation, there are increasing calls for impact assessments. This article argues that such assessments need to recognize the range of (...) ideational, institutional, economic and political factors and forces underpinning the turn to PPPs, and the very different logics and agendas involved, some of which seem quite contradictory from the perspective of equitable development and democratic governance. The article examines these different forces and logics, focusing on (a) the institutional turn towards "good governance", (b) economic contexts that relate to the very mixed "fortunes" of UN agencies and corporations, (c) structural determinants associated with "corporate globalisation" and (d) political drivers that relate to the struggle for hegemony and legitimisation. The article ends by reflecting critically on the tendency within mainstream development institutions and some strands of academic literature to highlight logics associated with good governance and pragmatism, and to disregard those associated with the strengthening of corporate interests and the neoliberal policy regime. It is argued that knowledge networks associated with the UN need to go beyond "best practice learning" and embrace "critical thinking", which has waned within UN circles since the 1980s. (shrink)