The aim of this study was to prospectively evaluate and compare the effects of radiofrequency thermocoagulation of the first division branches of the trigeminal nerve (trigeminal peripheral division radiofrequency thermocoagulation, PRT) versus conventional radiofrequency (CRF) in the treatment of first division idiopathic trigeminal neuralgia (ITN). Fifty patients with first division ITN were randomly divided into two groups. The 20 patients in group 1 were treated with CRF, while the remaining 30 patients in group 2 were treated using PRT. The immediate therapeutic effects, side effects and recurrence rate of idiopathic trigeminal neuralgia were evaluated. The immediate efficacy rates were 95% and 93% in groups 1 and 2, respectively. The recurrence rates of ITN at the 3-year follow-up were 25% and 27% for group 1 and group 2, respectively, and 35% and 40%, respectively, 5 years after treatment. There were no significant differences between groups 1 and 2 at any time. Our study demonstrates that PRT is an effective way to treat first division ITN.