We describe the stability of neuropsychologic testing in a 16-year-old boy with cerebellar dysgenesis who received 61 acute and maintenance electroconvulsive therapy treatments for malignant catatonia. Measures of nonverbal intelligence and visual memory before treatment onset and after 61 electroconvulsive therapy treatments indicated no evidence of decline in intellectual functioning and acute or delayed memory. This case offers further support for the safety and efficacy of maintenance electroconvulsive therapy in both pediatric and developmentally disabled populations.