The Global Fund to Fight AIDS, Tuberculosis and Malaria (the Global Fund or GFATM) is a private public partnership aimed at leveraging and providing funding for the three focal diseases outlined in its title. Set up in 2002, the fund was part of a new 'breed' of players in the field of global health, combining skills from bilateral and multilateral agencies with private sector and civil society. Highly innovative in its structure and funding model, the Global Fund's secretariat in Geneva provides grants directly to one or more organisations - not just governments - in recipient countries. Despite great successes, including scaling up treatment for AIDS to reach 4.2 million people, the fund has been the subject of intense debate. This includes discussion of its impact on health systems and allegations of financial irregularities among recipients in four countries. The organisation has now emerged with a new strategy, funding model and executive director. This paper charts its history, discusses some of the challenges faced, drawing on fieldwork conducted by the author in 2007-08, and reflects on recent changes and the road ahead.