SINCE Sament and Schwartz first called attention to hyperglycemic nonketotic coma in 1957, 23 similar cases have been reported.1-14 Extreme hyperglycemia, serum hyperosmolarity, and dehydration in the absence of ketosis and acidosis are the major components of the syndrome. Inasmuch as 44% of the patients that have been reported have died, the early recognition of this syndrome and prompt institution of proper therapy are essential. Three patients have been studied on the wards of this hospital and the results are reported to emphasize the importance of this entity, its treatment, and to propose a possible pathophysiological mechanism. Report of Cases Patient 1. —A 54-year-old Negro was hospitalized because of progressive weakness, drowsiness, and confusion for three days. For many years he had drunk a fifth of a gallon of whiskey each day and had not eaten more than one meal per day. He remained well until two months before