PURPOSE: To evaluate the preliminary results of endovascular coil treatment of acutely ruptured aneurysms. MATERIALS AND METHODS: Between August 1995 and December 1997, 18 patients with 20 ruptured aneurysms weretreated. They were classified as Hunt and Hess grade I (n=3), grade II (n=1), grade III (n=3), grade IV (n=10) orgrade V (n=1). Endovascular treatment was performed at mean 5.2 (range, 1-18) days. The first aneurysm was treatedwith mechanical detachable spirals (MDS) and the others with Guglielmi detachable coils (GDC). Aneurysm size wascategorized as small (n=17) or large (n=3). Ten aneurysms were located in the anterior circulation, and ten in theposterior circulation. Using the Glasgow outcome scale (GOS), clinical outcome was evaluated 5 to 27 months aftertreatment in 11 patients. Three patients had already died. RESULTS: In 14 of the 18 patients (16 of 20 aneurysms: 80%), treatment was successful. Four aneurysms failed due to unsuccessful catheter placement (n=2), smallaneurysm (n=1) or occlusion of the parent vessel (n=1). Total occlusion was observed in 13 aneurysms; 95-99%, orsubtotal occlusion, in two, and less than 95%, or incomplete occlusion, in one. Technical complications includedpassing of wire (n=1) and unintentional parent artery occlusion (n=1). There was a 7.1%(1/14) morbidity rate, butno mortality related to the technique. Six patients with Hunt and Hess grade I-III had good clinical outcome (3with GOS 1, and 2 with GOS 2). Four of the nine patients who were grade IV-V showed clinical improvement (GOS 3);two patients were clinically unchanged (GOS 4), and three died from the severity of primary hemorrhage. CONCLUSION: Endovascular coil treatment is a reasonable alternative for patients who are not candidates forconventional surgical treatment or in whom such treatment has failed.