Objective To investigate the clinical utility of keyhole craniotomy for Cholesteatmas in the cerebello-pontine angle region presenting as Trigeminal neuralgia by using keyhole craniotomy. Methods Clinical data of 35 pa-tients with Cholesteatmas in the cerebellopontine angle region presenting as Trigeminal neuralgia was analyzed retrospec-tively. All patients received suboccipital retrosigmoid keyhole craniotomy. Thirty cases who received conventional craniot-omy group were served as control group. A comparative analysis was conducted to assess the difference between these two groups in microsurgical methods, effects and complications. Results All patients were confirmed with MR diagnosis. In keyhole group, all patients had no pain symptoms of trigeminal neuralgia after surgical operation. The symptoms disap-peared immediately in 33 cases and gradually disappeared in 2 cases within one month following keyhole craniotomy. The tumors were totally removed in 25 cases and almost completely in 10 cases. The surgical duration was shorten in key-hole group than in conventional group (126±48 vs. 216±66 min;t=2.536, P<0.05). The amount of bleeding was smaller in keyhole group than in conventional group (91.3±52.2 vs. 186.3±65.4 mL;t=2.163, P<0.05). Postoperative neurologi-cal function was assessed in House-Brackmann. In keyhole group, there were 32 cases in class Ⅰ and 3 in grade Ⅱ. Two patients had hearing loss which was improved gradually in three months. In conventional group, there were 25 cases in class Ⅰ and 5 in grade Ⅱ (χ2=4.158, P<0.05). Postoperative hearing evaluation (AAO-HNS) revealed that there were 33 cases in grade A , and 2 in grade B in the keyhole group, whereas there were 27 cases in grade A and 3 in grade B in the conventional group(χ2=5.167, P<0.05). There were no relapse of tumors and death during 3 month to 5 years follow-up. Conclusions The suboccipital retrosigmoid keyhole craniotomy is a valid choice for Cholesteatmas in the cerebellopontine angle region presenting as Trigeminal neuralgia.