Choroid plexus cysts (CPCs) are the most common neuroepithelial cysts, occurring in more than 50% of some autopsy series. They are typically small and asymptomatic and are discovered incidentally in older patients, usually in the trigone of the lateral ventricle. Symptomatic CPCs (usually exceptionally large, 2-8 cm) are rare. The authors report a case of large symptomatic choroid plexus cyst, located in the trigone of the right lateral ventricle in a 26-yr-old man who presented with headache and vomiting. The patient underwent endoscopic removal through a burr hole placed 3 cm from the midline and just behind the hair line. The histological examination of the cyst wall was consistent with choroid epithelium. Despite of postoperative intraventricular hemorrhage and catheter infection, he discharged home without neurologic deficits. The endoscopic fenestration rather than excision should be considered as the first surgical procedure because the goal of treatment is shrinkage of the cyst until normal cerebrospinal fluid flow is restored.