Although the percentage of children who are malnourishes has declined in many countries of the developing world in recent years, the absolute number of malnourished children is rising in some regions, particulary in Sub-Saharan Africa. This paper aims to determine which of the various causes of mal nutrition are most important for the developing countries as a whole and by region, thus enabling policymakers to prioritize their investments and make the besy use of available resources to reduce malnutrition now and in coming years.