A prospective study of child health has been continued until the children were 36 months old. The mortality rate in the second year was 8.1%. The most common cause of death was chronic undernutrition. The 79 children suffered seventy-six episodes of faltering weight gain; 47 lost 0.5 kg, and most did not reach their former weight for 5 months. Marasmus complicated eighteen faltering episodes; three were fatal. Of 45 children remaining in Juba to their 36th month none had marasmus, and their health was improved. 15 of 53 children, mean age 2.25 years, showed developmental delay. After 10 months 7 showed continued delay. Hepatitis B seemed to be transmitted to the children from both mothers and other sources. Day-care centres can help chronically undernourished children, and health education should be directed towards the parents' capabilities.