The septo-optic dysplasia, or de Morsier syndrome, is a ventral midline developmental defect of the brain associated with hypoplasia of one or both optic nerves. Agenesis of the septum pellucidum, malformation of the forebrain, and hypothalamic-pituitary dysfunction are the caracteristic features of the brain. We experienced a case of septo-optic dysplasia in neonate. A magnetic resonance imaging of the brain showed absence of septum pellucidum, forming a single lateral ventricle. And fundoscopic examination noted both optic discs and optic nerve hypoplasia.