Surgical outcomes following repair of unruptured anterior communicating artery (AcomA) aneurysms have not been adequately addressed in the literature. We present our operative experiences in a consecutive series of 103 patients with 115 unruptured AcomA aneurysms. Clinical results, operative complications, angiographic outcomes and prognostic factors associated with surgery are presented. Of the 115 aneurysm repairs attempted, 114 were treated by clipping or excision and suture. One aneurysm, less than 2 mm, was wrapped. Six patients (5.8%; 95% confidence interval [CI], 2.5-12.4) experienced a new permanent neurological deficit. There was no postoperative mortality. Transient morbidity occurred in 11 patients (10.7%; 95% CI, 5.9-18.3), including transient anosmia (four patients), acute postoperative confusion and memory disturbances (four patients), extradural haematoma requiring surgery (two patients) and cerebrospinal fluid rhinorrhea (one patient). Of the 84 aneurysms (73.0%) that had documented postoperative angiography, 82 (97.6%) had complete obliteration of the aneurysm and two (2.4%) had neck remnants (mean angiographic follow-up 28.0 months; range, 1.6-146.4 months). Retreatment was performed in one patient (1.0%). Logistic regression analysis of risk factors revealed that aneurysm size (p < 0.01) was a significant predictor of outcome. There was no incidence of subarachnoid haemorrhage in the 272 person years of follow-up. In the current study, surgical treatment of unruptured AcomA aneurysms resulted in 5.8% morbidity and no mortality. The robustness of aneurysm repair achieved by open microsurgery is an important consideration when considering the option between endovascular and microsurgical treatment for unruptured AcomA aneurysms.