A 7-year-old patient presented with growth failure and early morning convulsions. The convulsions were associated with hypoglycemia and ketosis. Symptomatic hypoglycemia with ketosis occurred following the administration of a hypocaloric ketogenic diet. The diagnosis of hypopituitarism was established by failure of growth hormone response following administration of insulin and arginine hydrochloride, and failure of metyrapone to increase the urinary excretion of 17-ketogenic steroids. Thyroid function became abnormal. Therapy with thyroid extract alone and later combined with prednisone failed to decrease the frequency of ketotic hypoglycemic episodes. The administration of thyroid extract and human growth hormone, however, was followed by remarkable improvement which may have been due, in part, to increased insulin production.