We report a case of a patient with isolated central nervous system relapse of classical seminoma, refractory to intrathecal and systemic chemotherapy, but successfully salvaged with craniospinal axis irradiation. A 44-year-old man with bulky Stage II classic seminoma obtained complete remission with four cycles of cisplatin etoposide combination chemotherapy, but relapsed with lumbar vertebral metastases with epidural spinal cord compression 5 months after completion of primary treatment. He underwent laminectomy, local radiotherapy, and salvage chemotherapy. Two months later he developed cranial nerve palsies, and magnetic resonance imaging confirmed leptomeningeal disease. After brain radiotherapy, systemic and intrathecal chemotherapies were begun but tumor recurred around the cauda equina, producing paraparesis. The patient received salvage craniospinal irradiation, with resolution of paraparesis and cranial nerve palsies. Thirty months after completion of craniospinal radiotherapy, he remains in complete remission. We suggest consideration of craniospinal axis irradiation as salvage therapy in patients with isolated central nervous system relapse of seminoma.