A group of 525 people, originally studied with reference to diabetes in 1946, were restudied in 1950 and 1953. In the original group there were 294 classified as normal, 70 as diabetic, and 161 as suspect because of postprandial hyperglycemia. In 1953, 292 subjects remained available for study, and it was possible to draw certain conclusions as to the characteristics of diabetic and prediabetic patients. Persons classified as suspect were eight times as likely as the normals to appear later in the diabetic group. Abnormalities of the eyes, heart, and great vessels were found much more frequently in the diabetic than in the other two groups. The predictive value of comprehensive physical examinations was evident, and it appeared likely that further studies of this sort may yield hints as to prophylaxis against diabetes and its complications.