Direct Microsurgical intracranial approach is a standard technic for the treatment of ruptured intracranial aneurysms. Nevertheless aneurysms of the anterior communicating artery present particular difficulties because of their critical location, their various projections, the serious circulatory disturbances that may follow their rupture or vasospasm, the prevalence of local vascular anomalies, and their tendency for fatal recurrent hemorrhage. The authors analyzed 102 cases of anterior communicating artery aneurysms, surgically treated at Yonsei University Hospital in the Department of Neurosurgery from 1971 through August 1981. The operative mortality of the microsurgical pterional approach was 4.8% and the morbidity was 5.9% as compared to a mortality of 16.7% and a morbidity of 44.4% seen before the advent of microsurgery.