This paper reviews pastoralism in the Horn of Africa region with reference to the basic socio-economics of pastoralism, and the use of mobile livestock production to generate income and food for human consumption. The paper also examines long-term trends in pastoralist areas which, at first sight, appear to be contradictory. The first trend is the growth of a substantial domestic and export trade in livestock and meat across the region, driven largely by supplies from pastoralist areas and local and international demand. This trend indicates robust and responsive livestock production and marketing in pastoralist areas, despite recurrent drought, conflict and weak governance. In contrast, the second trend sees increasing levels of poverty and destitution in pastoralist areas, and continued high levels of human malnutrition. The co-existence of economic growth and increasing poverty in 'high-export' areas is explained by human population growth, drought, and the private control of pastures and water by wealthier producers. All of these factors combine to push poorer producers out of pastoralism. In areas with lower market orientation, other forms of declining land access are often evident, including the appropriation of land for mechanised farming, hydroelectric schemes, and bush encroachment. These changes, plus population growth and drought, also push people out of pastoralism. In all areas, pastoralism will continue to be the main economic activity but, at the same time, increasing numbers of people are seeking other livelihoods.