✓ Bilateral trigeminal neuralgia occurred in 32 (11.9%) of 269 consecutive patients who were treated with radiofrequency electrocoagulation (RFE). This is a higher incidence than has been reported before and may be explained by the prospective nature of the present study, the long follow-up period, and the inclusion of patients with mild bilateral symptoms. Multiple sclerosis is the most common predisposing factor and occurred in 18% of those with bilateral trigeminal neuralgia. Although patients with bilateral trigeminal neuralgia were more likely to have had prior surgery than those with unilateral neuralgia, they did not have a higher recurrence rate following treatment. Percutaneous RFE of the retrogasserian rootlets and gasserian ganglion, with or without glycerol, is effective in managing patients whose pain is intractable to medical therapy. The preservation of most trigeminal sensory and motor functions, the low morbidity rate, and the ability to repeat the procedure are particularly advantageous for patients with bilateral involvement.