Investigations in 30 healthy control subjects of Indian, Chinese and Malay ethnic origin, revealed that all the Chinese and about two thirds of the Indians and Malays had a normal capacity to absorb D—xylose, Vitamin A, Co58 labelled Vitamin B12 and dietary fat. About a third of the Indians and Malays were unable to absorb one or two of the four test substances used in the absorption studies. Jejunal biopsies did not differ in the 3 ethnic groups and were normal or mildly abnormal. 27 patients presenting with anorexia, a sore tongue and pallor were also investigated. Indians formed the majority of the patients. Diarrhoea occurred in only 51 % of the patients. All had a megaloblastic anaemia. Absorption studies revealed malabsorption of xylose, Vitamin A and Vitamin B12 in the majority but steatorrhoea occurred in only 26% of the patients. Jejunal biopsies were mildly abnormal in 8% and moderately or severely abnormal in 92 % of the patients. All responded to folic acid or Vitamin B12 therapy. 16 patients were restudied after 5 to 24 months therapy and the majority were found to have improved. Results of investigations and response to therapy indicate that these patients were suffering from tropical sprue. These studies indicate that tropical sprue in Singapore affects Indians mainly and can often present without diarrhoea and steatorrhoea.