All is not well for biodiversity in the tropics. Despite recent debate over the extent of future tropical extinctions and the effectiveness of reserve systems, the continued disappearance of habitat, soaring human population, and loss of vital ecosystem services demand immediate action. This crisis is worrying, given that tropical regions support over two-thirds of all known species and are populated by some of the world's poorest people, who have little recourse to lower environmental-impact lifestyles. Recent evidence has shown that - in addition to unabated rates of forest loss - coastal development, overexploitation of wildlife, catchment modification, and habitat conversion are threatening human well-being. We argue that the recent technical debate about likely extinctions masks the real issue - that, to prevent further loss of irreplaceable tropical biodiversity, we must err on the side of caution. We need to avoid inadvertently supporting political agendas that assume low future extinction rates, because this will result in further destruction of tropical biodiversity.