OBJECTIVE To assess the clinical benefit of ventriculoperitoneal shunting in patients suffering from radiotherapy-induced leukoencephalopathy. METHODS Retrospective review of a single institutional experience. METHODS Thirty-one patients with the postradiotherapy syndrome received ventriculoperitoneal shunts. All had a history of cranial irradiation, progressive ventriculomegaly visible on neuroimaging scans, and neurologic decline; other causes of hydrocephalus were excluded. All 31 patients had cognitive deficits: 30 had gait disturbance and 24 were incontinent. RESULTS Twenty-four (80%) of 30 assessable patients achieved symptomatic improvement an average of 1.6 months after ventriculoperitoneal shunting. Incontinence and gait problems were more likely to improve than cognition. Sixteen (53%) of 30 patients achieved a good overall functional outcome, and incontinence was the only feature significantly associated with good outcome (P=.04). Neither cerebrospinal fluid-opening pressure nor tap tests predicted improvement from ventriculoperitoneal shunting. Median duration of improvement was 6 months, and median survival after receiving the shunt was 14.5 months. Shunt-related complications occurred in 10 (33%) of 30 patients, with 1 fatal outcome. CONCLUSIONS Our results from ventriculoperitoneal shunting in selected patients with radiation-induced hydrocephalus suggest potential benefit. Improvement is incomplete and temporary, but can improve quality of life. Reliable predictors of successful shunt outcome were not identified.