Trigeminal neuralgia(tic douloureux) is a condition characterized by excruciating paroxysms of pain in lips, gums, cheek or chin. There are many treatments of trigeminal neuralgia, such as carbamazepine, electrical stimulation, radiation therapy and ablative procedures. We blocked the mandibular nerve via lateral extra-oral route with pure ethyl alcohol in patient with localized gingival pain. The results were as follows; 1) The mandibular nerve block with pure ethyl alcohol was effective. 2) No complications were noted.