The clinical results of surgery for unruptured aneurysms in the Neurosurgical Department of Kiel were analyzed to further discuss whether an operative treatment can be advised. Between 1991 and 2001, 54 unruptured aneurysms in 45 patients were operated in our department. No complications occurred in 38 patients; transient complications (slight aphasia, hemiparesis, psychiatric disorders) in 4 patients; postoperative seizures in one, epidural haematoma with the need of re-operation in one, and infection in another patient. At the time of discharge, GOS was 5 in 33 patients, 4 in 12 patients. But the slight disabilities were due to the aneurysm operation only in two patients, in the other 10 patients they were caused by pre-existing concomitant diseases. The Rankin-Scale after at least 6 months was 1 (no disability) in 31 patients (37 patients investigated); 2 (slight disability) in 5, and 3 (moderate disability) in one patient. In only one of these patients, the slight disability was caused by the aneurysm operation. During a telephone interview performed between 6 months and 7 years after the operation, all patients except two (31 patients investigated) gave a positive answer to the question, whether, in case of diagnosis of an aneurysm, they would undergo an operation again. Regarding our results, we still advocate treatment of unruptured aneurysms in patients who are in stable clinical conditions, especially in young patients and in patients with unique aneurysm configurations and aneurysm sizes approaching 10 mm.