BACKGROUND: Bilateral optic nerve hypoplasia (BONH) is often associated with other central nervous system midline abnormalities (septo-optic dysplasia). Hormonal dysfunction, caused by anterior (cortisol) and posterior (ADH) pituitary involvement, can be sudden, severe, and life threatening. METHODS: Case series. Three cases of septo-optic dysplasia (SOD) presenting as infantile infection with associated diabetes insipidus are reported. The diagnosis of SOD was suspected only after ophthalmological evaluation; further evaluation led to the diagnosis of panhypopituitarism. CONCLUSIONS: A high index of suspicion is required to diagnose SOD in children when the disorder presents with infantile infection and hypernatraemia. Early warning signs of neonatal jaundice and hypoglycaemia should prompt ophthalmological evaluation.