Headache is a common emergency department chief complaint. Although most are benign, emergency physicians must rapidly identify and manage the uncommon, sometimes subtle, presentation of headache from a life-threatening cause. Cerebral venous thrombosis imparts significant morbidity and mortality, and can be a challenging diagnosis. It most commonly occurs in those under 50 years of age with thrombosis of the cerebral veins/sinuses. Diagnosis is frequently delayed. The disease can present with 1 or more clinical syndromes, including intracranial hypertension with headaches, focal neurologic deficits, seizures, and encephalopathy. Diagnosis requires imaging. Treatment includes stabilization, management of complications, and anticoagulation.