BACKGROUND Carotid rete mirabile (CRM) is a physiological network between the external carotid and internal carotid systems in lower mammals. Very rarely, these arterial channels are observed in humans. METHODS We describe a 13-year-old girl with CRM who presented with acute hemiplegia after an operation for Dieulafoy's ulcer, a submucosal vascular anomaly of the stomach. Angiogram revealed hypoplasia of the bilateral internal carotid arteries. The abnormal network from the external carotid system was seen around the cavernous portion of the internal carotid arteries. The ophthalmic arteries were developed as the collateral pathway. CONCLUSIONS To our knowledge, this is the first pediatric case reported in the literature. CRM sometimes accompanies intracranial or systemic vascular disorders such as cerebral aneurysm and pseudoxanthoma elasticum. CRM is a unique pathological condition that presents as a hemorrhagic or ischemic cerebrovascular disorder.