The addition of conventional chemotherapy to irradiation has improved the outcome of children with malignant gliomas. The application of high-dose chemotherapy has been proposed as a possible way to increase the response rate and thus the survival in children with malignant brain tumours. High-dose etoposide (500 mg/m2/day x 3) and thiotepa (300 mg/m2/day x 3) followed by bone marrow transplantation were given to 22 patients (age range 4-20 years) with newly diagnosed or recurrent high-grade glioma. The response rate in the 14 assessable patients was 29% with one complete and three partial responses. 5 patients had stable disease, and 5 progressive disease. 2 patients died of treatment-related toxicity. Only 3 patients remain alive disease free 54, 60 and 65 months after high-dose therapy. For children with high-grade gliomas, survival using high-dose chemotherapy is no better than that reported with conventional treatments.