We studied nine patients with anorexia nervosa: five were "undernourished" and four were "well-nourished". The undernourished patients had significantly higher plasma growth hormone (GH) levels in a fasting state and higher GH rebounds following glucose administration. In four of these patients, GH levels decreased to normal after weight restoration. Decreased urinary follicle stimulating hormone (FSH) in three and plasma luteinizing hormone in six patients were not related to nutritional status; however, positive correlation was found between duration of illness and urinary FSH. Other results included decreased plasma testosterone in the one male, elevated plasma cortisol in five, and decreased 17-ketosteroid excretion in five patients. The results support elevated GH as secondary to starvation of anorexia nervosa and not an independent hypothalamic-pituitary disturbance. Other endocrine findings indicate hypothalamic-pituitary malfunction is not confined to GH.