We report a case of a premature very low birth weight infant who presented shortly after birth with idiopathic central diabetes insipidus that persisted beyond the neonatal period and has been successfully managed with intranasal 1-desamino-8-D-arginine vasopressin. Although this condition is rare in neonates, early recognition, evaluation, and therapy may prevent more severe morbidity. Long-term successful management resulting in normal growth and development during infancy can be achieved with intranasal 1-desamino-8-D-arginine vasopressin therapy.