IN this paper we present a clinical and analytical study of a case of eongenital steatorrhoea and compare it with the only previous example of the condition as yet reported. The term steatorrhoea, which has sometimes been used to cover all cases passing an obvious excess of fat in the stools (fatty diarrhoea, diarrhoea alba), is here used in its more correct and restricted sense, namely, as indicating a passage from the bowel of separated liquid fat which congeals on cooling (Butterstiihle). This phenomenon, which patients may describe as the passage of butter, oil, or grease, is one of comparative rarity. Acquired steatorrhoea is a well-known symptom. The most clearly defined of such cases are those associated with acquired disease of the pancreas, in which the steatorrhoea is regarded as due to a failure of the action of the pancreatic lipase. Indeed it is generally held, as Salomon has stated (5), that true steatorrhoea is observed only in pancreatic disease. Congenital steatorrhoea, in which the stools are abnormal from birth, has, so far as we know, only been studied in a single case up to the present time. This unique case was reported in 1913 by Garrod and Hurtley (3) under the title of Congenital Family Steatorrhoea.