Middle cerebral artery aneuryms account for aporoximately 20 percent of all intracranial aneurysms. The majority are located at the bbifurcation of M1 segment insylvian fissure. Incidence of formation of intracerebral hematoma with ruptured aneurysm and giant and infectious aneurysms are more common than with aneurysm in other locations. Clinical presentation of the MCA aneurysms are associated with symptoms of subarachnoid hemorrhage and mass effect. Symptoms of subarachnoid hemorrhage such as headache are indistinguishable from that associated with SAH from rupture of an aneurysm in any other location. But mass effect of large aneurysm, temporal lobe epilepsy and transient ischemic attack occur more frequently with aneurysms of the MCA. Complications of MCA aneurysm surgery can be divided into two group, one related to subarachnoid hemorrhage with aneurysmal rupture and the other to surgical procedure. Vasospasm is major cause of morbiduty and medical complications such as hypertension, cardiac arrhythmia, pneumonia and GI bleeding are frequently encountered. Operative complications include occlusion of MCA branch by improperly placed clip, retraction injury, intraoperative rupture.