Optimal control of diabetes should achieve not only euglycemia and normal levels of glycosylated hemoglobin but also absence of the reversible concomitants of diabetes such as red cell rigidity, hyperlipidemia, increased capillary permeability, enlargement of the kidneys, proteinuria, etc. Unfortunately, in most patients consistent euglycemia cannot be assured even with two daily injections of insulin. However, self-measurement of blood glucose as a guide to insulin taken before each meal and at bedtime can, in selected patients, increase the frequency of normal glucose levels without undue hypoglycemia.