Drylands (arid and semi-arid areas) cover approximately 40 per cent of the Earth's land surface. Although they are not as species-rich as more temperate or humid regions, they are home to many endemic species uniquely adapted to arid conditions. But much of this natural biodiversity is fragile, and held in a delicate balance that is easily affected by natural and human-induced environmental changes. This policy brief examines the current threats to biodiversity in dryland areas and suggests what we need to do to protect them. It concludes with a set of recommendations for policy makers working to conserve biodiversity in drylands.