Ultrasonographic, blinded assessment was made of the extent of hepatic steatosis in 55 children with severe malnutrition: undernutrition (n = 6), marasmus (n = 18), marasmickwashiorkor (n = 17), and kwashiorkor (n = 14). The children were examined on admission, in early recovery (considered as baseline), and again at discharge. Eleven healthy control children and eight of the previously malnourished children were studied as comparison groups. Both oedematous and non-oedematous malnourished children had significantly more steatosis than the comparison groups at each time. Children with oedematous malnutrition had significantly greater steatosis than non-oedematous children at admission. Half of the non-oedematous malnourished children had appreciable hepatic steatosis at both admission and at baseline. Hepatic fat was only slowly mobilised. The rate constant was 1.4 +/- 0.3%/day. One quarter of the children did not change steatosis grades during the period they were in hospital. There was no overall correlation between the extent of steatosis and liver size. Hepatic steatosis in childhood malnutrition is not confined to oedematous children: it is frequently present in marasmic and undernourished children. Its extent is not necessarily related to the degree of hepatomegaly and accumulated lipid is only slowly mobilised.