Objective: We retrospecively analyzed the outcome of 26 elderly patients to evaluate whether Cyberknife radiosurgery is an effective and safe mode of therapy for medically intractable trigeminal neuralgia(TN). Methods and Materials: Between March 2004 and May 2005,26 patients who failed or refused surgery or were not suitable candidates for invasive intervention were treated by Cyberknife rediosurgery. To obtain an accurate distortion-free localization of the trigeminal nerve, a CT cisternography was performed. The CT images were sent to the CyberKnife workstaion, where the trigeminal nerve was outlined. Radiosurgery doses of 60~64 Gy were delivered to the 80% isodose line prescribed to an 8-mm length of the verve, sparing the most proximal 3mm away from the trigeminal verve root entry zone. Theh median follow-up after Cyberknife rediosurgery was 15 months. Results: Preliminary results from a cohort of 26 patients undergoing Cyberknife radiosurgery for TN showed that pain relief was achieved in 13 patients within the first 24 hrs ager treatment. At last follow-up, 25 of the 26 study patients reported early pain relief within 7 days. The actuarial pain control rate was 96% at median follow up of 15 months, A relapse of pain (or loss of improvement) was observed in 2 patients. Three patients had hyperesthesia(11.5%), which was the only complication observed in our patients. Conclusion: With these results, authors assume that Cyberknife radiosurgery could be on of safe and effective therapeutic methods in elderly patients with sever medically intractable trigeminal neuralgia