ABSTRACTThis long‐term study of the natural history of glucose tolerance in the aged is now in its eleventh year. Of 411 nondiabetic persons screened on admission to the Jewish Home for the Aged (J.H.A.) since 1968, 15 per cent had abnormally elevated levels of postglucose blood sugar (PGBS) as compared with 25 per cent in the period 1964–1968. Fewer positive reactors were discovered with annual screenings and with the glucose tolerance test (GTT). Although the proportion of positive reactors and of diabetic‐type GTT curves was higher in subjects over age 80 than under age 80, there were 82 residents screened annually for five to nine years who retained normal glucose tolerance despite advancing age. The relatively lower rate of deterioration of glucose tolerance in the second period was attributable to: 1) the younger age of residents admitted since 1968, and 2) the diabetes‐oriented diet plus emphasis on exercise and prevention of obesity. The reactive hypoglycemia found in 6 per cent of the residents was asymptomatic, whereas iatrogenic hypoglycemia was usually symptomatic and often severe. This led to a deliberate policy of undertreatment. Dietotherapy induced a lasting remission in about 60 per cent of newly diagnosed cases of diabetes, often to the point of normal glucose tolerance. Early diagnosis of chemical diabetes, by postponing or obviating the need for antidiabetic therapy, reduced the incidence of iatrogenic hypoglycemia. Diabetes‐oriented measures are recommended for the aged in general, and for residents of homes for the aged in p