900 to 1000 new cases of primary brain tumour occur each year in Denmark, and half of them are gliomas. The treatment is cytoreductive surgery, followed by radiation therapy and chemotherapy. Radiation therapy has a definite place in the treatment of low-grade gliomas, but the timing is a matter of dispute. Patients with Glioblastoma Multiform should be treated with concomitant radiation therapy and temozolamide, followed by adjuvant temozolamide. Anaplastic astrocytomas should be treated with postoperative radiation therapy with or without adjuvant chemotherapy. Anaplastic oligodendroglioma should be treated with radiation therapy only.