Purpose: This study presents the results of peripheral glycerol injections in patients with idiopathic trigeminal neuralgia. Patients and Methods: The patients who either failed to respond to drug therapy or developed serious side effects were treated by means of glycerol injections. Medical records and questionnaires on 157 patients treated between 1983 and 1996 were evaluated. The minimum follow-up period for each patient was 4 years. Results: The study population included 65 males and 92 females. The right side (112 patients, 71%) was affected more commonly than the left. The most common distribution was in the second and the third trigeminal divisions. The initial success rate was 98%. Pain recurred in 60 patients and was most frequently recorded between 25 and 36 months postinjection (28 of the 60 recurrences). These patients were successfully reinjected. At the end of 4 years, complete or almost complete pain relief was obtained in 154 patients. Conclusions: Peripheral glycerol injection is a minimally invasive and useful technique to manage trigeminal neuralgia, with a high success rate and low incidence of morbidity. © 2001 American Association of Oral and Maxillofacial Surgeons.