Objective ‒ to assess the incidence of infectious complications in patients with aneurysmal subarachnoid hemorrhage (SAH); to determine the effect of the complicated course of aneurysmal SAH on the incidence of nosocomial infection.Materials and methods. The results of treatment of 250 patients in the acute period of aneurysmal SAH were analyzed, among them 124 observations (49.6 %) were identified, in which a complicated course of aneurysmal SAH was stated. In 185 cases, endovascular coiling was used to occlude the ruptured aneurysm, and in 65 cases the aneurysm was clipped. A group of patients who underwent infectious complications in the acute period of aneurysmal SAH was identified. The latter included: pneumonia, urinary tract infections, ventriculitis and meningitis.Results. The median age was 48.95 years (range 14 to 74 years). By gender, the majority were women ‒ 144 (57.6 %). Infectious complications were diagnosed in 52 (20.8 %) patients. Pneumonia was noted in 48 (19.2 %) cases. Urinary tract infections were observed in 36 (14.4 %) patients, in 7 (2.8 %) cases, infection of the nervous system (meningitis in 3 cases and ventriculitis in 4 cases). In the group of infectious complications, there were more observations referred to the group of complicated course of aneurysmal SAH ‒ 49 (92.3 %). Patients with severe SAH according to the WFNS, Hunt-Hess scales and the Fisher radiological scale prevailed. The average value was: WFNS ‒ 3.1 and Hunt‒Hess ‒ 3.7, according to the Fisher scale ‒ 3.5. Mortality in the group of infectious complications was 38.5 % (20 cases).Conclusions. Infectious complications occur with a frequency of 20.8 % and are a factor that worsens functional outcome and increases mortality in patients with aneurysmal SAH. Primary brain damage after rupture of an aneurysm, which determines the severity of SAH and the complicated course of the disease, is a predictor of the development of infectious complications.