This chapter is intended to provide an overview of radiotherapy for central nervous system (CNS) tumors; radiotherapy in arteriovenous malformations (AVMs) and functional neurosurgery are beyond the scope of this chapter. Goals of radiotherapy are palliative and curative and also as a preoperative adjuvant. Radiotherapy is determined by CNS tolerance, the volume of normal tissue exposed, dose per fraction and total dose. Delays between surgery and radiotherapy should be avoided. A radiation dose of about 60 Gy over periods of about 6 weeks is the routine. Shorter treatment schemes may be appropriate for the elderly patients. Role of altered fractionation, brachytherapy and radiosensitizers is unproven. Craniospinal irradiation is indicated in tumors such as primitive brain tumors, ependymomas, lymphomas, etc. The current technologic advances in radiotherapy such as, three dimensional techniques and image fusion can improve the therapeutic index to only a limited extent. SRS and CyberKnife are often recommended for residue and recurrent tumors, as well as inaccessible benign tumors.