The Zambezi River Basin lies across southern tropical Africa, with significant portions in Angola, Zambia, Zimbabwe, Malawi and Mozambique and smaller portions in Namibia, Botswana and Tanzania. Its total extent is approximately 1.33 million km2. The Zambezi River itself rises in northwestern Zambia on the Central African Plateau which covers much of the continent. It first drains south then eastwards, and exits into the Indian Ocean north of Beira in Mozambique. In this paper an outline of the evolution of the Zambezi Basin is given, followed by an account of our knowledge on the vegetation types, plants, vertebrates and invertebrate species found there. Particular reference is given to those species of ecological or economic significance. Areas and species of particular interest from a conservation viewpoint are mentioned, and the conservation threats are outlined.