Background. This Phase 11 study was designed to determine response to chemotherapy and survival after response-based radiation (RT) in children with CNSgerm cell tumors. Procedure. Children With germinomas and normal markers received cisplatin 100 mg/ m(2) +etoposide, alternating with vincristine+cyclophospharnide (CPM) 2 g/m(2)/d, for four cycles. Children with nongerminomatous tumors or with abnormal markers received doubled doses of cisplatin and CPAA. For germinoma patients in complete response (CR), RT was decreased from 50.4 to 30.6 Gy. High-risk patients received neuraxis RT: 50.4 Gy local+30.6 Gy neuraxis in CR; 54 Gy local + 36 Gy if less than CR. Results. Of 12 germinoma patients, 4 had cerebrospinal fluid (CSF) human chorionic gonaclotropin (HCG) 6.9-21 mIU/ml. Of 14 nongerminomatous patients, HCG in serum or CSF was > 50 mIU/ml in 9, of.-fetoprotein (AFP) abnormal in 9. Four germinoma patients attained CR, six PR, one SD, one not evaluable after resection. Two nongerminornatous patients had CR, three PR, three SE), one PD, four not evaluable after resection; one inadequately treated patient had progressive disease (PID). Both PID patients died; one SID patient died during a seizure. Eleven germinorna patients are PF at median 66 months; one patient in CR refused RT, had PD at 10 months, received RT, and was PF at 56 months. Eleven of 14 nongerminomatous patients were PF at median 58 months. Conclusion. Response (germinoma, 91%; nongerrninomatous, 55%) and survival are encouraging after this regimen plus response-based RT.