Biodiversity – a measure of the wealth of species, ecosystems and ecological processes that make up our living planet –received public prominence as a result of the Earth Summit in Rio de Janeiro in June 1992. The loss of biodiversity, say the authors, is the greatest environmental problem the world faces but the issue has not been given the attention it deserves. With the emergence of the Global Environmental Facility in 1990 came the chance to fund biodiversity conservation on a unprecedented scale and in 1992 the GEF was adopted as the interim funding mechanism for the Convention on Biological Diversity signed at the Earth Summit. Three years after its foundation, the authors of this paper suggest that the GEF has to be reformed radically if it is to become an effective force in conservation. Their conclusions are based on Conservation International's experience with the GEF over the last 3 years in more than 10 countries.