In this book the biodiversity conservation status, problems, efforts and prospects in parts of the Horn of African countries representing Djibouti, Eritrea, Ethiopia and Somalia are reviewed. The ever-growing human population of >100 million, and various socio-economic, environmental and cultural issues are indicated as challenging the implementation of biodiversity conservation programs in this region. This region has diverse types of ecosystems such as highlands, Afro-alpine, lowlands, deserts and coastal areas with varied topography, and vegetation types correlated with the level of precipitation in the respective areas. The biodiversity of the Horn of African region is also endowed with high level of endemism. Two biodiversity hotspots, viz., the Horn of Africa biodiversity hotspot and the Eastern Afro-montane biodiversity hotspot occur in the region. Over 1,300 plants and animals species of the region listed in the IUCN red list categories. Many of the biodiversity resources of the region have high potential for human use. However, detailed studies on the biodiversity resources of the Horn of Africa region and its conservation are yet to be undertaken.