OBJECTIVE: The goal of this study was to evaluate the effect of Gamma Knife radiosurgery(GKS) on cerebral arteriovenous malformation(AVM) and the factors associated with complete occlusion. PATIENTS AND METHODS: A total of 369 radiosurgical procedures for 336 patients with cerebral AVMs were performed between December 1988 and June 2001. Three hundreds and twenty-four cases of 293 patients who were treated with GKS procedures from May 1992 to December 2000 were analyzed. Various clinical and radiologic parameters were evaluated. RESULTS: The total obliteration rate for the cases with satisfactory radiological follow-up(more than 2 years) after GKS was 79.3%. In multivariate analysis, maximal diameter, angiographic form of AVM nidus, and number of draining veins significantly influenced the result of radiosurgery. In addition, marginal radiation dose, Spetzler-Martin grade, and flow pattern of AVM nidi also partly influenced the radiosurgical outcome. CONCLUSION: GKS on cerebral AVM is considered as an effective treatment modality. The risk of hemorrhage seems to decrease within the latency interval between GKS and complete occlusion of nidus. Along with the size, topography, or radiosurgical parameters of AVMs, it is necessary to consider the angioarchitectural and hemodynamic aspects to select proper candidates for radiosurgery.