Surgical or medical ovarian ablation is likely to be the treatment of choice at the current time, radiation ablation (RA) can be still a reasonable alternative. The efficacy and toxicity of radiation therapy (RT) for ovarian function suppression in 118 premenopausal breast cancer patients were retrospectively evaluated. The median age was 39 years (range 21-52 years). RT was given with either Co-60 or 15MV photons of the linear accelerator. The median total dose was 15Gy in 4 consecutive fractions (range 5Gy single fraction-36Gy in 18 fractions over 3.5 weeks). The endpoint for treatment efficacy was menstrual status. Amenorrhea was noted in 113 of 118 patients (96%) in 6 months following RA. Five patients (4%) who had still normal menstrual functioning after 6 months of RA underwent estradiol and follicle stimulating hormone measurements and were found to have premenopausal levels. No acute Grade 3 or 4 (according to the Radiation Therapy Oncology Group radiation morbidity scoring criteria) toxicities were noted. With a median follow-up of 24.5 months (range: 6-167), no late severe complications that could be attributable to RT were reported. RA should be considered as an option for endocrine responsive premenopausal breast cancer patients and can be easily delivered when postoperative or palliative irradiation is given.