Moyamoya disease is a chronic, progressive occlusion of the circle of Willis arteries that leads to the development of characteristic collateral vessels seen on imaging, particularly cerebral angiography. The disease may develop in children and adults, but the clinical features differ. Moyamoya disease occurs predominantly in Japanese individuals but has been found in all races with varying age distributions and clinical manifestations. As a result, moyamoya disease has been underrecognized as a cause of ischemic and hemorrhagic strokes in Western countries. At this time, there is no known cure, and existing treatment options are controversial. The authors describe the case of a 44-year-old African American woman with a history of hypertension, cervical cancer, breast cancer, and stroke who was diagnosed as having moyamoya disease. A review of the literature for the various facets of this condition is also provided.