Electroconvulsive therapy was successfully used to treat malignant catatonia in a 15-year-old male patient with congenital dysgenesis of the left hemisphere of the cerebellum and hypoplasia of the vermis and left pons due to a presumed cerebral vascular accident in utero. The patient experienced significant motor and communication delays with mild cognitive impairment, but was otherwise in good health until age 15 years, when he developed rigidity, posturing, stupor, unresponsiveness, repetitive self-injurious behaviors, and negativism, as well as autonomic abnormalities including profuse diaphoresis and flushing episodes, thus meeting criteria for malignant catatonia. After initial response to lorazepam, the patient required electroconvulsive therapy for resolution of malignant catatonia. The case supports the safe and efficacious usage of electroconvulsive therapy for catatonia in adolescents with cerebellar and other developmental disorders. The role of the cerebellum in catatonia is also reviewed.