The mortality rate of pediatric CNS cancer has not decreased in the same proportion as other tumours in children. High grade gliomas have a unfavorable prognosis with few therapeutic options. The objective response rate (ORR) of these tumours to chemotherapy ranges from 11% to 27%, in the best of cases. Relapsed high-grade gliomas and intrinsic brain stem tumours have a uniformly fatal outcome despite all the treatments tested. The treatment of adults with de novo glioblastoma after surgical resection is local radiotherapy concomitant to temozolomide. This approach in children is still under clinical assessment. In the case of low-grade astrocytomas, the indication for adjuvant therapy is limited to patients with unresectable tumours that also cause a neurological lesion. Although they are slow growing tumours, they can cause severe morbidity and are life-threatening. Radiotherapy has known side effects on the nervous system in children. Chemotherapy is used to delay or avoid radiotherapy in these patients.