The OBJECTIVE was to determine the efficacy of endovascular surgery for in-hospital acute ischemic stroke (AIS) and to identify predictors of unfavorable AIS outcome.METHODS AND MATERIALS. We performed 42 endovascular thrombectomies for in-hospital AIS in patients treated in the hospital for another pathology. Neurological defiCIT was determined by NIHSS scale, thrombectomy efficacy was evaluated by the degree of cerebral revascularization by mTICI scale, functional outcome was determined by Rankin scale (mRS). Multivariate analysis with evaluation of clinical and laboratory, neuroimaging data, and analysis of surgical technique was performed to identify factors contributing to adverse stroke outcome.RESULTS. The mean age of patients was 73.8±11.8 years old. Neurological defiCIT before surgery was 12.8±6.7 points by to NIHSS. Thrombolytic therapy was used in one third of cases, thrombectomy in 92.9 %, and carotid artery stent ing in 2 cases. Successful revascularization (mTICI2b-3) was achieved in 83.3 % of cases. The significant reduction in neurological defiCIT after surgery was achieved to NIHSS 6.0±5.9 points, mRS 2.7±2.1. The mortality rate amounted to 16.7 % of cases. Poor functional outcome (mRS3-5) was significantly associated with: female gender, older age, presence of cardiovascular pathology, recurrent stroke, postoperative tachycardia, low renal tubular filtration rate, hypocoagulation, low cardiac ejection fraction, low aortic valve opening amplitude, high pulmonary hypertension, large left atrial volume, initial severe neurological defiCIT, poor collaterals in the area of cerebral ischemia, proximal internal carotid artery occlusion, hemorrhagic saturation, increased operation time, low degree of revascularization (mTICI0-2a).CONCLUSION. Endovascular surgery has demonstrated its safety and high efficacy in the treatment of in-hospital AIS in surgical hospitalized patients. Endovascular thrombectomies allow to significantly reduce neurological defiCIT and decrease mortality in the severe category of patients with cardioembolic AIS. clinical, laboratory, hemodynamic and neuroimaging factors influencing on poor functional outcome of in-hospital AIS have been determined.