Hypopituitarism is a common complication of TBI in long-term survivors, more frequent than previously realized. It may be partial or complete, sometimes very subtle without visible lesions in hypothalamo-pituitary region and is diagnosed only by biochemical means. Neuroendocrine abnormalities caused by TBI may have significant implications for the recovery and rehabilitation of these patients. The subjects at risk are those who have suffered moderate to severe trauma, although mild intensity trauma may precede hypopituitarism also. Particular attention should be paid to this problem in children and adolescents. We describe a patient with hypopituitarism thought to be idiopathic due to mild head trauma which caused diabetes insipidus in childhood, gradual failure of pituitary hormones during the period of growth and development, and metabolic (dyslipidemia), physical (obesity), and cognitive impairments in the adult period.