Most patients with brain aneurisms were operated on in the late posthemorrhagic period at the Burdenko Neurosurgical Institute. Objective. To investigate the rate and structure of complications of microsurgical and endovascular surgery for different topographic anatomic variants of cerebral aneurysms in patients operated on in the late posthemorrhagic period in order to assess the risk of intervention in these patients. Material and methods. The study group comprised 1074 patients with single brain aneurysms who had been treated at the Burdenko Neurosurgical Institute (Russian Academy of Medical Sciences) for the period from 2005 to 2012. The exclusion criterion for the study was the acute stage - 21 days after the date of hemorrhage. Age of patients ranged from 18 to 75 years, with the mean of 45.3 years. The number of female patients was 552 (51.4%); the number of male patients was 522 (48.6%). Microsurgical operations were performed in 887 (82.6%) patients, endovascular - in 187 (17.4%). Results. Postoperative complications were observed in 163 (15.2%) patients. Most of the complications (14.2%) were associated with cerebral disorders. Pronounced deterioration was noted in 6% of cases, death - in 0.9%. Cerebral complications were revealed in 13.8% of the patients after microsurgery and in 16% after endovascular treatment; mortality was observed in 1% and 0.5%, respectively. Conclusion. The overall risk of disability and death associated with recurrent hemorrhage from the aneurysm, especially at young age, is significantly higher than risks of surgical intervention in patients in the late posthemorrhagic period. Thus, the presence of a brain aneurysm that caused hemorrhage is an indication for surgical treatment, regardless of the time of its rupture.