OBJECTIVE To compare the use of electrolytically detachable coils versus surgical ligation for the management of acutely ruptured intracranial aneurysm. METHODS A prospective randomized study included 109 patients with acute (< 72 hours) subarachnoid hemorrhage caused by a ruptured aneurysm (Hunt and Hess grade I-II [n = 67], grade III [n = 26], or grade IV-V [n = 16]). All patients were suitable candidates for both endovascular and surgical treatment and were randomly assigned to undergo coil embolization (n = 52) or surgical ligation (n = 57). RESULTS Significantly better primary angiographic results were achieved after surgery in patients with anterior cerebral artery aneurysm (n = 55, P = .005) and after endovascular treatment in those with posterior circulation aneurysm (n = 11, P = .045). No significant differences were seen in middle cerebral artery (n = 19) or internal carotid artery (n = 24) aneurysms. Early rebleeding occurred in one patient after incomplete coil embolization. The technique-related mortality rate was 4% in the surgical group and 2% in the endovascular group. Clinical outcome (Glasgow Outcome Scale score) at 3 months was not significantly different between treatment groups in terms of intended treatment modality. No late rebleedings had occurred at the time of this writing. CONCLUSIONS In selected patients with a recently ruptured intracranial aneurysm, favorable results were achieved by using endovascular treatment. Subsequent acute or late open surgery was sometimes required. The clinical outcome at 3 months was comparable in the endovascular and surgical treatment groups.