Medulloblastoma is the most common malignant brain tumor of childhood. Although the survival rate of afflicted children has improved considerably over the past several years, a subset of these patients will present with disseminated disease and face a much bleaker prognosis. In addition, patients may present with disseminated disease at recurrence. We previously demonstrated the efficacy of a recombinant oncolytic measles virus (MV) to treat localized medulloblastoma in a mouse xenograft model. In the present study, we sought to extend our findings to the treatment of disseminated disease. To this end, we developed and characterized a mouse xenograft model of disseminated medulloblastoma using serial bioluminescent imaging techniques in combination with histopathological examination. Mice injected with medulloblastoma cells into their right lateral ventricle showed tumor growth in their ventricles and in both intracranial and spinal subarachnoid spaces, closely recapitulating the human disease. Subsequent intraventricular administration of MV resulted in stabilization and shrinkage of the tumor, significantly prolonging the survival of the treated animals, compared with those treated with an inactivated virus. These data demonstrate that oncolytic MV may be of use in treating disseminated medulloblastoma. In addition, our protocol of intraventricular tumor cell injection, followed by bioluminescent imaging coupled with histopathological examination, provides a model for use in evaluating future recombinant oncolytic viruses and other preclinical therapeutic approaches for disseminated medulloblastoma.