Arteriovenous malformations of the brain generally make their presence felt before the age of 40 through cerebromeningeal hemorrhage (83 cases) or epilepsy (47 cases). In our series, 128 patients were operated upon and total resection of the malformation was performed on 119 occasions. The operative mortality rate was 12.5% and there were 70.3% good results from a long-term point of view. The essential benefit from surgical treatment is the elimination of the risk of hemorrhage. The effect on epilepsy is much less, and the natural development of nonhemorrhagic forms is not unfavorable over the long term. The prognosis for surgical treatment is linked to the size and the topography of the malformation, the number and the origin of the arterial afferent vessels, and, above all, to the mode of drainage into the venous system that may be malformed.