Quantitative serial measurements of Alpha-fetoprotein (a-FP) and Beta-human chorionic gonadotropin (B-HCG) using radioimmunoassay were performed in a patient with recurrent non-germinomatous germ cell tumor (NGGCT) into CNS during radiotherapy and chemotherapy. When the pineal tumor was initially presented, elevated levels of serum a-FP and B-HCG fell dramatically to normal rage after the completion of cranial irradiation (5,060cGy). Three months later, the patient had a rise in serum and CSF tumor markers coincident with recurrence of tumor into lumbal spinal canal. Serum levels were not changed despite of 15 days of whole spine irradiation (2,000cGy) although decreased remarkably 1 month after the completion of radiotherapy (4,230cGy). At the time of relapse in the suprasella area and the cerebellopontine angle, serum and CSF levels rised again. As a result of two courses of chemotherapy the tumor markers fell markedly, but the tumor was spread to other sites into CNS. We conclude serial measurements of a-FP and B-HCG are useful for the diagnosis of the non-germinomatous germ cell tumor into CNS and for monitoring disease activity.