A neoadjuvant (preradiotherapy) chemotherapy regimen consisting of either cyclophosphamide alone (60 to 80 mg/kg) or a modified multidrug regimen (vinblastine, bleomycin, cyclophosphamide, and cisplatin) was administered to 15 newly diagnosed patients with histologically confirmed, fully staged, primary germ-cell tumors (GCT's) of the central nervous system (CNS). There were 11 patients with germinomas and four with non-germinoma malignant GCT's. There were six females and nine males, whose median age was 13 years (range 4 months to 24 years). Seven germinoma patients (64%) had disseminated disease. For the germinoma patients, the subsequent radiotherapy dose was modified based on the response to the neoadjuvant chemotherapy, and craniospinal radiotherapy was given only to those with disseminated CNS disease at diagnosis. Ten of the 11 germinoma patients had complete disappearance of all evaluable disease after two courses of chemotherapy (cyclophosphamide in eight and multidrug in three) and one had a partial response. The planned dose of radiotherapy to the primary tumor was reduced from 5500 to 3000 rads, and the craniospinal dose was lowered from 3600 to 2000 rads. Ten patients remain in continuous disease-free remission 20+ to 89+ months after diagnosis (median follow-up period 47 months). All four patients with non-germinoma GCT's received the multidrug regimen, and two fo three patients with evaluable disease had a partial response. High-dose regional and craniospinal radiotherapy was administered thereafter, but only two patients remain in their first remission. Previously untreated germinoma is a highly chemosensitive disease and the neoadjuvant treatment strategy permits the identification of active chemotherapy regimens in newly diagnosed patients. Patients who have complete responses to neoadjuvant chemotherapy tolerate a significant radiotherapy dose reduction without compromising long-term survival, thereby allowing a reduction of some of the late effects of therapeutic radiation. Germinomas tend to disseminate early in the course of the disease and a pre-therapy staging evaluation permits individualized radiotherapy treatment planning.