High dose chemotherapy (HDCT) with autologous (bone marrow or peripheral blood) stem cell rescue (ASCR) has had success in the treatment of some malignant pediatric brain tumors. We report a series of adults enrolled in one of three HDCT and ASCR protocols for malignant primary brain tumors. Overall toxic mortality was 18%; chemotherapy regimen, tumor type, and prior treatment did not predict transplant-related mortality. Patients over the age of 30 had a higher rate of toxic mortality. Patients with recurrent medulloblastoma had a significant improvement in long-term survival (median: 34 months) as compared with historical reports; two patients with glioblastoma survive beyond four years without progression, but overall, a significant improvement in long-term survival could not be demonstrated for malignant gliomas.