A series of 44 cases is presented of patients who received surgical treatment for unruptured aneurysms in the anterior circulation, and which were associated with ischemic cerebrovascular disease (CVD). The age of patients varied from 34 to 76 (mean 62.8) years old. The associated ischemic CVD was transient ischemic attack (TIA) in ten, minor completed stroke in 23, and major completed stroke in 11 cases. Thirty five patients recovered fully. However, there were three deaths due to new cerebral infarction or delayed intracranial hemorrhage within 30 days after surgery (mortality 6.8%). Transient morbidity occurred in four patients (9.1%), and permanent morbidity in two patients (4.5%). In six cases, new ischemic events occurred after the surgery. In contrast, all 40 patients whose unruptured aneurysms were not associated with CVD fully recovered from the surgery they underwent. The authors indicate three risk factors which might lead to complication; diabetes mellitus, aneurysms located in the middle cerebral artery, and those larger than 6mm in diameter. Another three life-threatening factors are; elderly patients (> 65 year-old), male, aneurysms larger than 7mm in diameter. Direct surgery for unruptured aneurysms in ischemic CVD patients should be considered in cases free of risk factors indicated above. Eight cases in this series had extracranial carotid artery stenosis on the same side as the aneurysm. Carotid endoarterectomy (CEA) was performed prior to aneurysmal clipping in six patients, and their postoperative courses were excellent. In two patients, clipping was performed prior to CEA, and transient morbidity occurred in one of them.(ABSTRACT TRUNCATED AT 250 WORDS)