To evaluate the long-term obliteration and toxicity outcomes of arteriovenous malformation (AVM) treated with hypofractionated stereotactic radiotherapy (HSRT). Retrospective analysis of 40 patients treated for AVMs from 2004-2007 was performed. All the patients were treated with LINAC-based HSRT in five consecutive daily fractions to a prescription dose of 35 Gy using a median isodose line of 80% to the periphery. Eleven patients were lost to follow up and the remaining 29 were included in this study. Patients underwent regular follow up with MRIs and subsequent cerebral angiography for confirmation of nidus obliteration. Acute and long-term toxicity data were collected including rates of symptomatic radiation necrosis (RN), cerebral cyst formation, intracranial hemorrhage (ICH), and death. The median follow-up was 13 years (range 0.9-15.3 years). 20 (69%) were male and 9 (31%) were female. The median age at treatment was 44 years (range 14-62). The most common presenting symptom was intracranial hemorrhage (ICH) (13 pts; 45%). Five patients underwent embolization prior to HSRT. Four lesions were in eloquent locations (13.8%), defined as basal ganglia, thalamus, or brainstem. The median greatest diameter and volume measured 3.9 cm (range 1.8-8.7) and 11.43 cc (range 1.33-108.55), respectively. Median modified Radiosurgery Based AVM Score (mRBAS) was 2.02 (range 0.51-12.45). 23 of the 29 lesions obliterated (79%) with median time to obliteration of 3 years. 25 of the patients (86%) experienced radiation-induced adverse effects. 18 patients (62%) had symptoms that persisted beyond three years post-treatment. Eight patients (28%) had cerebral cyst formation. Seven patients (28%) underwent resection of chronic RN with a median time to surgery of 8 years. Four patients suffered post-treatment ICH with one patient death from associated complications. The experience at this single institution illustrates the importance of long-term follow up in evaluating the treatment of AVM with LINAC-based HSRT. While the obliteration rate of 79% is above average for the treatment of large AVM, a toxicity rate of 86%, which included chronic RN and cyst formation requiring intervention may substantially complicate long-term management and negatively impact quality of life. Risk of long-term HSRT complications must be weighed carefully against risk of hemorrhage and other complications associated with conservative management and open surgery for these lesions.