A rteriovenous malformations (AVMs) are abnormalities of the intracranial vessels that constitute a connection between the arterial and venous systems and lack an intervening capillary bed. 7,19,22,25,30,34 According to reports, 0.1% of the population harbors an AVM, 3,8 and both sexes are equally affected. AVMs are the leading cause of nontraumatic intracerebral hemorrhage in people less than 35 years old. 37 Most lesions come to patients' attention in their 40s and 75% of the hemorrhagic presentations occur before the age of 50 years. 7 In addition, AVMs can cause debilitating headaches, seizures, and progressive neurological deficits due to ischemia of the surrounding abbreviatioNs AVM = arteriovenous malformation; DSA = digital subtraction angiography; GKS = Gamma Knife surgery; HR = hazard ratio; NBCA = N-butyl cyanoacrylate; RAS = Radiosurgery AVM Scale; RIC = radiation-induced change; SRS = stereotactic radiosurgery. obJective A combination of embolization and radiosurgery is used as a common strategy for the treatment of large and complex cerebral arteriovenous malformations (AVMs). This study presents the experiences of partially embolized cerebral AVMs followed by Gamma Knife surgery (GKS) and assesses predictive factors for AVM obliteration and hemorrhage. methods The interventional neuroradiology database that was reviewed included 404 patients who underwent AVM embolization. Using this database, the authors retrospectively analyzed all partially embolized AVM cases followed by GKS for a residual nidus. Except for cases of complete AVM obliteration, the authors excluded all patients with radiological follow-up of less than 2 years. Logistic regression analysis was used to analyze the predictive factors related to AVM obliteration and hemorrhage following GKS. Kaplan-Meier analysis was used to evaluate the obliteration with a cutoff AVM nidus volume of 3 cm 3 and 10 cm 3 . results One hundred sixty-two patients qualified for the study. The median patient age was 26 years and 48.8% were female. Hemorrhage presented as the most common symptom (48.1%). The median preembolization volume of an AVM was 14.3 cm 3 . The median volume and margin dose for GKS were 10.92 cm 3 and 16.0 Gy, respectively. The median radiological and clinical follow-up intervals were 47 and 79 months, respectively. The annual hemorrhage rate was 1.71% and total obliteration rate was 56.8%. Noneloquent area (p = 0.004), superficial location (p < 0.001), decreased volume (p < 0.001), lower Spetzler-Martin grade (p < 0.001), lower Virginia Radiosurgery AVM Scale (RAS; p < 0.001), lower Pollock-Flickinger score (p < 0.001), lower modified Pollock-Flickinger score (p < 0.001), increased maximum dose (p < 0.001), and increased margin dose (p < 0.001) were found to be statistically significant in predicting the probability of AVM obliteration in the univariate analysis. In the multivariate analysis, only volume (p = 0.016) was found to be an independent prognostic factor for AVM obliteration. The log-rank (Mantel-Cox) test of the Kaplan-Me...