The first-line management for idiopathic trigeminal neuralgia (ITN) is medical therapy. The effectiveness of medications typically wanes over time,so we need to evaluate other modality of therapy. Objective: To compare pharmacotherapy versus Gamma knife radiotherapy (GKRS) in relief of pain in patients with idiopathic trigeminal neuralgia (ITN). Methods: the study included sixty eight patients with idiopathic trigeminal neuralgia. They were assessed by Barrow Neurological Institute (BNI) pain intensity scale. They were classified into two groups: Group I: 34 patients, were treated by GKRS and were chosen from Gamma knife center in Nasser institute hospital. They were 19(55.9%) male and 15 (44.1%) female with ages ranged from 40-59 years (Mean±SD was 49.5±6.1). They were assessed by BNI scale before and immediately after GKRS, One month and three months after GKRS treatment. Group II: 34 patients, were chosen from neurology department Zagazig University Hospitals. They were 19 (55.9%) male and 15 (44.1%) female with ages ranged from 40-60 years (Mean±SD was 49.0±6.95). They were assessed by BNI scale before and one week after pharmacotherapy, One month and three months after pharmacotherapy. Results: There was no statistically significant difference between the two groups regarding pain intensity before GKRS or pharmacotherapy (p=0.33) while one week after pharmacotherapy ten (29.4%) patients showed statistically significant improvement of pain.After one month, group I showed statistical significant better outcome (41.2%) than group II (8.8%). BNI score three months after managements was highly statisticallly significant better (32.4%) among group I than group II (p=0.001). Most of group I (82.4%) had good overall outcome while 50% of group II had fair outcome and26.5% had good outcome.Conclusion: medical management of ITN had an initial good results in improving pain intensity which begins to wane over one month and the effect of GKRS begins to appear. The effect of GKRS on ITN pain is still evolving through three months follow up.