We conducted a retrospective study of the outcomes of 17 patients who underwent gamma knife radiosurgery (GKRS) for idiopathic trigeminal neuralgia (TN) with a minimum 3-year follow-up. The median interval from GKRS to pain improvement was 4 weeks (range, 1-16 weeks). At the last follow-up, a good treatment outcome was verified in 16 (94.1%) patients (Barrow Neurologic Index pain score, I-IIIb). One patient (5.9%) had treatment failure. On follow up, six patients (35.3%) had a recurrence of pain following some initial relief. Mean time to pain recurrence was 20 months (range, 3-36 months). Four patients (23.5%) experienced treatment-related complications. Three patients reported some degree of post-treatment facial numbness. One patient reported decreased corneal sensation (dry eye syndrome). GKRS is a safe and effective long-term treatment method for TN and should be considered as an alternative option for medically intractable TN.