Abstract: We report on a 30-year-old woman diagnosed with moyamoya syndrome resulting from sickle cell disease who developed catatonia and was successfully treated with electroconvulsive therapy (ECT). Neuroimaging revealed severe tandem narrowing of the left internal carotid artery with diminished cerebral blood flow, moderate narrowing of the right supraclinoid aspect of the right internal carotid artery, and associated numerous lenticulostriate collaterals bilaterally, consistent with moyamoya. The patient presented with mutism; posturing; immobility; stupor; withdrawal; refusal to eat, drink, or speak; and staring, supporting a diagnosis of catatonia. It initially responded to a lorazepam challenge; however, a complicated hospital course and deterioration of the patient’s condition, including septic shock, delirium, and continued catatonic symptoms, led to the pursuit of ECT to treat her symptoms. We discuss the risks involved with the administration of ECT in a patient with fragile cerebral vasculature and the successful treatment of catatonia in this patient without resultant stroke or cerebral hemorrhage.