A total of 100 consecutive patients, (93 with ruptured aneurysms, 7 with asymptomatic aneurysms) were managed following a radio clinical investigation protocol. Preoperative evaluation included clinical grading (Hunt and Hess) (20 patients were GR I, 43 GR II, 19 GR III, 9 GR IV and 9 GR V) angiography and CTScan grading. The timing of surgery was determined according to angiographic, clinical and CTScan data: 73.2% of ruptured aneurysms were operated on between Day 0 and Day 3. Control angiography and control CT were performed 10-12 days after surgery (earlier in case of clinical deterioration). Post operative CTScan hypodensities were evaluated according to preoperative CT, preoperative angiography and post operative angiography: 32 hypodensities (8 without any symptom) were related to initial hemorrhage, vasospasm or post surgical thrombosis. In five cases the etiology was dobble. Angiographic control data showed 18 cases of vasospasm and 12 cases of post surgical thrombosis. We did not find any complication due to the control angiography. The outcome was classified according to the Glasgow Outcome Score (GOS): of 82 GR I.II.III (H & H) cases, the outcome was 73 GOS 1-2 cases, 3 GOS 3 Cases, 1 GOS 4 case and 5 GOS 5 cases. of 18 GR IV.V (H & H) cases, the outcome was 4 GOS 1-2 cases, 1 GOS 3 case, 1 GOS 4 case and 12 GOS 5 cases. In 28 GOS 2-3-4-5 cases, the cause of disability or death was under the main responsibility of the initial hemorrhage 13 times, of a thrombosis 11 times, of the vasospasm 4 times with associated non neurological problems in seven cases. When the control angiography is not performed and when the thrombosis is unrecognized sequellae or death can be erroneously attributed in many cases to the sole vasospasm or to the initial hemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS)