Manifestations of pheochromocytoma include stroke, acute myocardial infarction, acute pulmonary edema and sudden cardiac arrest. Progressive cerebral angiopathy is a rare and life-threatening presentation of pheochromocytoma. We describe the case of a patient who presented to our Emergency Department with thunderclap headache; fluctuating high blood pressure and seizure were noted, but initial brain imaging study revealed no significant findings. Despite a high suspicion of pheochromocytoma, the patient responded poorly to medical therapy. Repeat brain computed tomography (CT) revealed diffuse brain swelling, uncal herniation and brain stem injury. The patient died on the 4th day of hospitalization due to progressive cerebral angiopathy secondary to pheochromocytoma.