Endovascular treatment of cerebral aneurysms has rapidly evolved and has transformed neurosurgical practice. We evaluated the influence of an interventional neuroradiology service on cerebral aneurysm management. We performed a retrospective analysis of all aneurysms treated in our unit before and after the establishment of endovascular treatment. All patients (n = 248: 78M: 170F aged 10-78 years) who underwent aneurysm treatment between 1996 and 1999 were included in the analysis. Length of in-patient stay on neurosurgical ward, GOS at 6-month follow-up and complications of treatment were the factors chosen for the analysis. Definitive treatment was attempted in 306 of 374 aneurysms detected (203 surgical and 103 endovascular). During the last 2 years of the study period, 46% of all aneurysms were coiled. Endovascular treatment of ruptured aneurysms tended to be sooner than surgery, but in-patient stay following treatment was the same. No significant difference in GOS at 6-month follow-up was found (chi2 = 0.18). Coiling of unruptured aneurysms reduced in-patient stay when compared with surgery (t-test, p < 0.001), fewer complications occurred, but no difference in outcome was seen at follow up (chi2 = 1.09). Our data suggest that the long-term morbidity following subarachnoid haemorrhage is not related to treatment modality. Coiling is the preferred treatment for unruptured aneurysms. The GOS is insensitive to the detection of the perceived benefits of coiling. The increasing role of interventional neuroradiology has direct effects on many aspects of neurosurgical practice.