Fifty-seven patients with malignant germ cell tumors (GCTs) treated at our center between 1962 and 1979 were evaluated to determine 1) the prognostic value of disease stage, tumor histology, primary site, and patient age; 2) results of therapy; and 3) patterns of metastasis. The 35 girls and 22 boys were from 1 week to 18 years old (median 5 yr). Primary sites were ovarian (20), testicular (10), sacrococcygeal (12), retroperitoneal (7), mediastinal (5), and other (3). Cox regression analysis indicated that stage was the most important prognostic variable. Extragonadal tumors were usually advanced at diagnosis, but tumor site did not have prognostic value independent of disease stage. Neither patient age nor tumor histology significantly influenced outcome. Drugs active against malignant GCTs included vincristine, cyclophosphamide, and dactinomycin in combination and vinblastine, bleomycin, and cis-platinum. Radiation alone cured nondisseminated germinomas. The most common sites of metastasis were lungs, liver, central nervous system, and bone; other sites were infrequently involved. We conclude that stage was the most important prognostic variable, extragonadal tumors were usually advanced at diagnosis, and similarities in the histogenesis, metastatic pattern, and response to therapy, regardless of primary site, justify the consideration of childhood malignant GCTs as one group.