The etiology of many types of epilepsy is still unsolved. The term cryptogenic as used in this article defines cases in which there is no definite pathologic condition. 1 It may well be that some of the manifestations of this disease are of metabolic origin; therefore, an accumulation of biochemical data is of the utmost importance. Thus far few observations on cholesterol have been published. Perhaps the most comprehensive investigations are those carried out by Robinson, Brain and Kay 2 and by Osnato and his co-workers. 3 Although their findings are interesting, we considered further work necessary. This report presents observations on the occurrence of cholesterol and lecithin in the blood in forty-seven cases of epilepsy and in the spinal fluid in twenty cases. The patients were all inmates of the Manhattan State Hospital. The blood was drawn in the morning before breakfast. Cholesterol was determined according to the Myers