Fat balances were studied in 41marasmic children and 26 healthy controls, for periods of 6 days, during which the dietary intake of fat was 15 to 45 g daily. The control group excreted 8.0±0.37 g% of an average intake of 33.4±0.61 g fat per day. In the 27 marasmic children without steatorrhoea, the excretion of fat in faeces was the same as that in healthy children. Definite steatorrhoea, over 10% of ingested fat excreted, was observed in the other 14 marasmic children. Of those, 10 had mild to moderate steatorrhoea and excreted 15.49 1.06 g% of a daily intake of 28.20±2.49 g, and the 4 with severe steatorrhoea excreted 54.65±14.29 g% of an intake of 30.91±1.40 g fat per day. Barium meal tests on marasmic patients with steatorrhoea revealed the flocculation and dilatation of small bowel loops with puddling of barium, characteristic of fat mal absorption. No anatomicalabnormalitieswere detected. All except one of the 5 with steatorrhoea who were treated had normal fat excretion after treatment. PMT