The Bill & Melinda Gates Foundation is a major contributor to global health; its influence on international health policy and the design of global health programmes and initiatives is profound. Although the foundation's contribution to global health generally receives acclaim, fairly little is known about its grant-making programme. We undertook an analysis of 1094 global health grants awarded between January, 1998, and December, 2007. We found that the total value of these grants was US$8.95 billion, of which $5.82 billion (65%) was shared by only 20 organisations. Nevertheless, a wide range of global health organisations, such as WHO, the GAVI Alliance, the World Bank, the Global Fund to Fight AIDS, Tuberculosis and Malaria, prominent universities, and non-governmental organisations received grants. $3.62 billion (40% of all funding) was given to supranational organisations. Of the remaining amount, 82% went to recipients based in the USA. Just over a third ($3.27 billion) of funding was allocated to research and development (mainly for vaccines and microbicides), or to basic science research. The findings of this report raise several questions about the foundation's global health grant-making programme, which needs further research and assessment.