Annual retrospective surveys of 20 to 31 medical centers performing endovascular treatment of cerebral aneurysms in Japan from 1997 to 2008 were performed to analyze technical and clinical outcomes of endovascular treatment for ruptured cerebral aneurysm. Patients treated with dome embolization using bare platinum coils within 14 days after onset were retrospectively selected, and clinical features, and technical and clinical outcomes at discharge were studied. Retrospective Endovascular Subarachnoid Aneurysm Treatment (RESAT) 1 covers patients treated from 1997, when the Guglielmi detachable coil was introduced, to 2002, just after International Subarachnoid Aneurysm Trial was reported. RESAT 2 to RESAT 7 were conducted annually between 2003 and 2008. Among 5,624 patients with ruptured aneurysms treated within 14 days after onset, 4,782 patients were treated by dome embolization using platinum detachable coils. The patients in this large retrospective survey included 35.8% aged over 70 years, 36.6% with posterior circulation aneurysms, and 29.3% with poor grades (Hunt and Kosnik grades IV and V). The proportion of patients aged over 70 years tended to increase each year from 33.4% in RESAT 1 to 39.8% in RESAT 7, and the proportion of those with posterior circulation aneurysms decreased from 44.2% in RESAT 1 to 23.8% in RESAT 7 (p<0.001). Overall technical success was obtained in 4,666 patients (97.6%), and favorable clinical outcome (good recovery and moderate disability) at discharge was obtained in 88.0% of grade I-III cases and 73.6% of grade I-V cases. Procedure-related morbidity was 2.9% and mortality was 0.8%. Despite this survey involving high proportions of aged, posterior circulation, and poor-grade patients, the technical success rate and immediate clinical results were relatively favorable. The patient prognosis and aneurysm changes must be investigated over a longer period, together with the effects of the introduction of new endovascular devices for cerebral aneurysms.