We report on the successful use of electroconvulsive therapy in a 13-year-old boy with congenital hydrocephalus, a history of multiple shunt revisions, and a stable prepontine arachnoid cyst, who experienced profound catatonic deterioration. After initial shunt placement at age 20 months, the patient had followed normal motor, cognitive, and social developmental trajectories. Two uncomplicated shunt revisions were performed at ages 10 and 13 years. Three months after the last revision, the patient demonstrated multiple psychomotor signs, culminating in hospital admission for rigidity, posturing, waxy flexibility, stupor, mutism, and cessation of all oral intake. An extensive neurologic workup related to his preexisting conditions produced negative results, and a course of electroconvulsive therapy for acute catatonia was pursued, with outstanding improvement.