BACKGROUND: Intracranial pathology is a well-documented feature of mucopolysaccharidoses (MPSs), including communicating hydrocephalus (CH). Neither the success nor the complications of cerebrospinal fluid shunting in MPS patients have been well documented. OBJECTIVE: To retrospectively analyze 13 children with communicating hydrocephalus and MPS at our institution between 1998 and 2006. METHODS: Thirteen patients diagnosed with MPS I, II, or III presenting for stem cell transplantation were retrospectively analyzed. Patients underwent a rigorous pretransplantation workup, including magnetic resonance imaging of the brain. If imaging revealed ventriculomegaly, a lumbar puncture was performed. If intracranial pressure was >20 cm H20 or the patient demonstrated clinical signs of hydrocephalus or evidence of clinical decline with increasing ventricular size on imaging, a ventriculoperitoneal shunt (VPS) was placed. Clinical outcomes were analyzed after dividing the patients into 2 groups: patients who underwent VPS before (group A) and after (Group B) stem cell transplantation. RESULTS: There were 8 patients in group A and 5 in group B. Group B patients developed more severe complications, including 2 patients who required VPS early after transplantation, one who died secondary to intracerebral hemorrhage and another who developed a subdural empyema. Of the 8 patients in group A, 5 had complications, including 2 shunt infections, a punctate intracerebral hematoma, shunt tube migration, and 3 shunt failures. CONCLUSION: This is the largest review of MPS patients with communicating hydrocephalus. It demonstrates that VPS is an effective treatment. MPS patients need to be evaluated for hydrocephalus before stem cell transplantation because pretransplantation shunting appears to have the most favorable risk/benefit ratio.