Thirty-six patients with recurrent medulloblastoma were treated with various combination chemotherapy protocols after initial treatment (usually irradiation) failed. Use of systemic chemotherapy was limited by depressed bone marrow reserves secondary to previous craniospinal irradiation. Intraventricular and intrathecal therapies included cytosine arabinoside (Ara-C), methotrexate, and thio-tepa given as single agents. Major systemic agents used alone or in combination included CCNU, procarbazine, vincristine, and the hexitol epoxides. Patients were reirradiated with or without misonidazole when there was definite tumor progression after all other therapies failed and/or because myelosuppression was so severe that further chemotherapy was not possible. Sequential systemic or intrathecal chemotherapy and reirradiation produced median survivals of two years and 25% quartile survivals of 2.9 years. The prognosis for patients harboring recurrent medulloblastoma has improved considerably over the years because of the therapeutic approaches reported here.