Conservation non-governmental organisations (NGOs) have excited a great deal of comment and debate, generally quite divided, in diverse journals. Some advocate them as forces for good, others decry their clumsy dealings with rural peoples and the impoverishment their activities can cause. The debate suffers in two ways. First, it ignores a large parallel literature about the work of development NGOs. Second, there is a paucity of general knowledge about the state of the conservation NGO sector. We do not know where it works, what the main players are doing, or much at all about the extent or activities of the smaller conservation organisations. We do not know how much money the sector spends. In this paper we first briefly outline why work on development NGOs should be applied to conservation NGOs, and then offer an overview of the sector's activities based on a survey of over 280 organisations. We describe some of the basic contours of these activities, and reflect on the implications of our findings for existing writings about conservation NGOs and future research.