Colloid cysts of the third ventricle are rare intracranial tumors, accounting for 0.5% of intracranial tumors. Colloid cysts represent 2% of gliomas, are more common in men than women, and usually are diagnosed between the third and fifth decades of life. The primary presenting complaint of this disorder is headache. The headaches are described as intermittent, severe and intense, and of short duration and usually are located frontally. The main associated features are nausea and vomiting. The headache can be relieved by lying down, which is unusual for headaches secondary to intracranial tumors. Colloid cysts of the third ventricle are diagnosed by computed tomography or magnetic resonance imaging and treatment is surgical. This rare type of headache disorder is significant because it is associated with sudden death. Recognition of the unusual features of colloid cyst headache may result in decreased mortality in this disorder.