Gonadal germ cell tumors respond favorably to chemotherapy either at diagnosis or when they recur. Histologically similar tumors may arise in the CNS usually in the pineal or suprasellar regions. Although radiation therapy may produce a 5 year disease-free survival in excess of 60% in localized pure germinoma, germ cell tumors of other histology tend to recur. We have conducted 14 chemotherapy trials in 8 patients with recurrent CNS germ cell tumors using 3 different single agent and 2 multi-agent chemotherapy regimens. The histologic diagnoses of the patients were germinoma (4), endodermal sinus tumor (2), embryonal carcinoma (1), and mixed tumor - germinoma plus choriocarcinoma (1). There were 7 males and 1 female with a median age of 13 years. The primary tumor arose in the pineal region in 6 and was multicentric in 2. Seven patients had local recurrences and one developed an initial recurrence in the spinal canal. Three patients had CNS metastases at relapse and 2 had systemic metastases. Objective responses were documented in 7 of 14 trials (50%). Responses were observed with cyclophosphamide (80 mg/kg) in 3 of 4 patients for 2+, 3, and 5 mos, cisplatin (120 mg/m2) in 1 of 2 patients for 2+ mos, and the VAB 6 protocol (vinblastine, bleomycin, cyclophosphamide, actinomycin-d, cisplatin) in 3 of 5 patients for 5, 8, and 18 mos. The median duration of response was 5 mos. (2+-18). High doses of single chemotherapy agents such as cyclophosphamide and cisplatin as well as VAB 6 regimen have definite activity in recurrent CNS germ cell tumors, especially germinoma. Good palliation may be achieved with chemotherapy alone with acceptable morbidity.(ABSTRACT TRUNCATED AT 250 WORDS)