Objective To assess the results of microvascular decompression (MVD) in treating cranial nervehyperactive dysfunction. Methods From October 2002 to January 2007, 106 patients with cranial never hyperactivedysfunction were treated with MVD. Among them, there were 47 males and 59 females with an average age of 62 years (42-85 years), including 56 cases of trigeminal neuralgia, 33 cases of hemifacial spasm and 17 cases of spasmodic torticoll is. MRI showed obvious nerve root compression in 60 patients (56.6%), suspected nerve root compression in 33 patients (31.1%) and no nerve root compression in 13 patients (12.3%). The disease course was 2-300 months with median course of 54 months. The typical manifestations before operation were pain and myospasm in corresponding innervation region. Results The superior cerebellar artery was the most common offending vessel in trigeminal neuralgia (44.6%, 25/56), the anterior inferior cerebellar artery in hemifacial spasm (33.3%, 11/33), and the vertebra-basilar artery in spasmodic torticol is (82.4%, 14/17). Compl ications of facial paralysis, hypoacusia, facial numbness, dizziness, pain of neck and shoulder, muscles weakness of neck and subcutaneous dropsy occurred in 31 patients (29.2%). All patients were followed up for 6-42 months. The total response rate was 90.6%. The curative rate of MVD was 83.9% (47/56) in trigeminal neuralgia, 81.8% (27/33) in hemifacial spasm and 41.2% (7/17) in spasmodic torticol is, respectively. Five patients failed to response (4.7%), 2 of them were cured after re-operation and 3 abandoned further treatrment. Five patients suffered recurrence 3-8 months after operation (4.7%), 2 of them recovered after re-operation, 1 got rel ief by Gamma-knife treatment, and 2 abandoned further treatment. Conclusion MVD has a good therapeutic effect on the disease caused by vascular compression of cranial nerve. Comprehensive preoperative evaluation, skillful operational technique and intraoperative electrophysiological monitoring should be implemented to enhance the therapeutic effects of MVD and to prevent possible compl ications.