Objective To investigate the factors for prognosis and safety of patients with trigeminal neuralgia (TN) undergoing gamma knife surgery (GKS).Methods A total of 92 patients with TN who underwent GKS were enrolled and followed up to observe the time to pain relief and marked response, time to recurrence, and adverse events. The influencing factors for prognosis were analyzed.Results Course of disease (risk ratio [RR]= 0.505, 95% confidence interval [CI] 0.297-0.859, P=0.012), distance between target and pontine margin (RR=0.556, 95%CI 0.333-0.929, P=0.025), and history of operation (RR=5.127, 95%CI 1.746-15.052, P=0.003) were independent risk factors for time to marked response after GKS. History of operation (χ² = 5.628, P=0.018) and course of disease (χ² = 3.863, P=0.049) were associated with time to recurrence after GKS. The Cox survival analysis showed that history of operation and course of disease were not independent risk factors for time to recurrence after GKS (P=0.089 and 0.458). Compared with the group with distance between target and pontine margin ≥8 mm, the group with distance between target and pontine margin <8 mm had a higher incidence rate of adverse events (χ² = 3.993, P=0.046).Conclusions Course of disease <3 years, short distance between target and pontine margin, and no previous surgery were positive factors for the time to marked response after surgery. A short distance between target and pontine margin may cause an increase in adverse events.