Prospective clinical trials support the view that malignant neuroectodermal tumors should be treated vigorously using a multimodal approach that includes surgical resection, high-dose radiation therapy, and prolonged maintenance chemotherapy. Less malignant astrocytomas and oligodendrogliomas should be treated by resection and irradiation. Laboratory research on neuroectodermal tumors has advanced rapidly, providing new data on tumor cell biology and the pharmacology of chemotherapy that directly influence the therapeutic options.