We performed double high-dose chemotherapy followed by peripheral blood stem cell transplantation (PBSCT) in 3 children with medulloblastoma and primary leptomeningial dissemination, including spinal metastasis. After resection of the main tumor mass, 30.6 Gy whole craniospinal radiation therapy and 4 or 5 courses of conventional chemotherapy with vincristine (1.5 mg/m), carboplatin (560 mg/m), ifosfamide (9000 mg/m), and etoposide (500 mg/m), and 2 courses of high-dose thiotepa (680 mg/m) and melphalan (240 mg/m) therapy with PBSCT were administered. Two patients with low erythroblastic leukemia viral oncogene homolog 2 (ERBB2) gene expression achieved long-term survival (41 mo and 40 mo) but the patient with high ERBB2 expression relapsed 9 months after the second PBSCT.