Background: Trigeminal neuralgia (TN) is a well-known facial pain syndrome characterized by excruciating paroxysmal shock pain attacks located in somato-sensensory distribution of trigeminal nerve.  Mandibular affection is a common presentation of TN. Objectives: Studying the effect of injection of mandibular nerve with neurolytic solutions in trigeminal neuralgia that was unresponsive to pharmacotherapy. Patients and Method: This prospective study included 21 patients treated for mandibular neuralgia by percutaneous injection of absolute alcohol under guidance of CT image. Their ages ranged from 35-60 years and male to female was 3:4. All patients suffered from moderate to severe TN, and did not respond to medical treatment. Entry and trajectory of needle was planned by CT and after local anesthesia. Alcohol was injected at the exit of mandibular nerve from foramen ovale.            Results: 85.7% of patients improved (71.4% became pain free and severity of pain decreased in 19%), while 9.6% of patients has no response after injection. The pain free patients became 61.9% after two years of follow up.  Conclusion: CT guided mandibular nerve block by neurolytic agent as absolute alcohol and showed its effectiveness as minimal invasive treatment option for intractable trigeminal neuralgia. CT guidance provided a clear view to secure the safety, accuracy and selectivity of nerve block.