Severe malnutrition is defined by a weight for height below 70% of international standards or by presence of oedema in a clinically undernourished child. Severe malnutrition associated with oedema is called kwashiorkor. The origin of oedemas of kwashiorkor is still debated, but its relation with protein deficiency is strongly questioned. The same dietary management is now recommended for malnutrition with or without oedema. Present recommendations are based, as for well nourished children, on the separate estimation of nutritional requirements for maintenance and growth. Total requirements vary between 0.7 g/kg/day in the first few days of treatment to 5 g/kg/day or more when weight gain is maximum. As a result of high energy requirement during catch-up growth, protein requirements never exceed 10 to 12% of total energy needs.