OBJECT: The surgical management of patients with intracranial aneurysm continues to be controversial, but the best results of treating an aneurysm can be achieved with treating it before it ruptures. The purpose of this study is to evaluate the surgical risk of treating unruptured intracranial aneurysms. METHODS: Between January 2000 to December 2007, 46 unruptured intracranial aneurysms were treated with aneurismal neck clipping. The clinical outcome was retrospectively evaluated according to the Glasgow Outcome Scale about one month after surgery. RESULTS: The patients consisted of 24 females and 22 males. The mean age was 56.6 years (range: 37-80). For the aneurysm location, 27 (58.8%) were at the middle cerebral artery, 10 (21.7%) were at the anterior communicating artery, three (6.5%) were at the posterior communication artery, two (4.3%) were at the internal carotid artery, two (4.3%) were at the anterior choroidal artery, one (2.2%) was at the anterior cerebral artery and one (2.2%) was at the vertebral artery. The size of the aneurysm was below 5mm for 6 patients (13%), 6 to 10mm for 30 patients (65.2%), 11 to 25mm for 9 patients (19.6%) and > or =25mm for 1 patient (2.2%). The clinical outcome was good for 39 patients (84.8%), moderate disability was noted for 5 patients (10.9%) and severe disability was noted for 2 patients (4.3%). CONCLUSION: In this study, the morbidity and mortality rates were favorable compared with those of the previous reports. Our results suggest that aneurysms associated with a ruptured lesion or those larger than 10mm could be considered for treatment. These results will be very helpful to determine whether or not to proceed with surgery.