A prenatally diagnosed patient was referred to our hospital at 35 weeks of gestation. Antenatal ultrasonography demonstrated cardiomegaly and aneurysm of the vein of Galen. A 3,290 g male baby was delivered by elective cesarean section at 37 weeks of gestation. Physical examination was remarkable for tachypnea, hyperdynamic precordium with a continuous murmur, cranial bruit and bounding carotid pulses. Magnetic resonance angiography confirmed vein of Galen aneurysmal malformation and demonstrated the vessels feeding the aneurysm. Postnatal management included aggressive medical treatment of cardiac failure and transarterial embolization of the vessels feeding the aneurysm at 3 days of age. Posthemorrhagic hydrocephalus developed after embolization, and a ventriculo-peritoneal shunt was placed at 29 days of age. Presently, the patient is 4 years of age and has no neurological abnormality at follow-up. Vein of Galen aneurysmal malformations can cause severe morbidity and mortality in neonates. However, careful obstetric follow-up and early postnatal endovascular treatment of these malformations may lead to a favorable outcome. Copyright (C) 2011 Elsevier Taiwan LLC and the Chinese Medical Association. All rights reserved.