Trigeminal neuralgia (TN) is a chronic pain condition causing lancinating pain in the distribution of one or more divisions of the trigeminal nerve. Gamma knife stereotactic radiosurgery (GKSRS) is a surgical option for TN refractory to medical therapy. To report our experience and to analyze the reasons for the variance in radiosurgery outcomes between patients in our diverse population, we conducted a retrospective analysis of a prospectively created database. The 178 patients completed a pain assessment questionnaire before surgery, and at 1 and 2 year follow-ups. We used the “Trigeminal Neuralgia Gamma Knife Outcome Scale” (TN GKOS) to report the response. At 1-year, 35.4% of patients had grade 1A outcome (pain-free and off all pain medications), 24.7% had grade 1B (pain-free on pain medications), 24.2% had grade 1C (some pain but improved with radiosurgery), 12.9% had grade 2 (same as before radiosurgery) and 2.8% had grade 3 (worse pain compared to before radiosurgery). At 2 years, 42.3% had grade 1A, 20.5% had grade 1B, 19.2% had grade 1C, 14.1% had grade 2 and 3.8% had grade 3 outcome. Remarkably, a statistically significant association was found between GKOS and age, racial background and obesity.