To determine the patterns of puberty associated with the syndrome of septo-optic dysplasia, 13 older children with optic nerve hypoplasia and hypopituitarism were studied. Three patterns of puberty were observed: early, rapidly progressive puberty (group 1); appropriately timed puberty (group 2); and delayed puberty associated with gonadotropin deficiency (group 3). In the six patients in group 1, puberty began at an early bone age. Pubertal changes progressed rapidly and the bone age advanced faster than chronologic time so that, despite a normal to increased growth rate, growth potential was lost. Group 2 comprised three patients with multiple pituitary hormone deficiencies but without gonadotropin deficiency who had the timing and progression of puberty expected in hypopituitarism. The four patients in group 3, all with multiple pituitary hormone deficiencies, had gonadotropin deficiency requiring sex steroid replacement.