AIm:The study deals with intraoperative rupture of intracranial aneurysms (IOR) during microsurgery, analyzing factors that may be connected with IOR. mAterIAl and methOds: During the three-year period (2006)(2007)(2008), 934 patients were operated for aneurysms at the Institute of Neurosurgery, CCS, Belgrade. In total, 536 patients were observed.results: IOR occurred in 14.7%. Male gender, seizures and timing of surgery proved to be risk factors for IOR. All other tested features had no significance. Localization {IOR rate 11.93% in ACM, 17.06% in ACA and 17.26% in ACI) and size (small: IOR in 68/439 (15.49%), large: 8/74 (10.8%), and very large: 3/23 (13.04%)} of aneurysm seemed to have an influence, but this could not be proved. The majority of IORs (58.23%) occurred in early surgery. Early operated patients: IOR occurred in 46/167 (27.54%), intermediary: 25/103 (24.27%), and delayed: 8/266 (3%) -with highly significant differences.COnClusIOn: Age, hypertension, diabetes mellitus, cardiomyopathy, pregnancy, higher Fisher score, previous IOR, or the presence of vomiting and headache did not affect the occurrence of IOR, whereas the timing of surgery, male gender and epileptic seizures increased the risk. Localization and size of aneurysm tend to have an influence but statistical significance was not proved in this study. sOnuÇ: Yaş, hipertansiyon, diabetes melitus, kardiyomiyopati, hamilelik, daha yüksek Fisher puanı, önceki İOR, veya kusma ve bulantı bulunması İOR varlığını etkilemezken cerrahinin zamanlaması, erkek cinsiyet ve epileptik nöbetler riski arttırmıştır. Anevrizmanın yeri ve büyüklüğünün bir etkisi var gibidir ama bu çalışmada istatistiksel önem ispatlanmamıştır.
