The research investigates the efficacy of brain transcatheter laser revascularization in patients who have had extensive ischemic stroke. 1125 patients aged 29 - 81 (average age 75) with cerebral atherosclerosis were examined. The examination plan included: CT brain scan, magnetic resonance imaging (MRI), brain scintigraphy (SG), rheoencephalography (REG), cerebral multi-gated angiography (MUGA), laboratory tests, assessment of severity of dementia (CDR), cognitive impairment (MMSE) and activities of daily living (IB). 93 patients suffered extensive ischemic stroke of whom 7 (7.53%) had 10 - 15 IB points, 25 (26.88%)—20 - 30 IB points, 61 (65.59%)—35 - 45 IB points. 69 patients underwent transcatheter treatment (Test Group). 24 patients underwent conservative treatment (Control Group). High-energy laser systems were used for revascularization of major intracranial arteries; lowenergy laser systems were used for revascularization of distal intracranial branches. Test Group: 67 (97.10%) patients had good immediate angiographic outcome manifested in the restoration of lumen and patency of the affected vessels as well as in collateral revascularization. 12 - 24 months later the following positive trend was observed: 14 (20.59%) patients demonstrated good clinical outcome (IB 90 - 100); 26 (38.24%) patients had satisfactory clinical outcome (IB 75 - 85); 28 (41.18%) patients showed relatively satisfactory clinical outcome (IB 60 - 70); relatively positive clinical outcome (IB < 60) was not obtained in any case. Control Group: 4 (16.67%) patients showed relatively satisfactory clinical outcome (IB 60 - 70), relatively positive clinical outcome (IB < 60) was achieved in 20 (83.33%) cases. Evaluating the data obtained, it can be concluded that the method of transluminal laser revascularization of cerebral blood vessels is an effective one for the treatment of extensive ischemic strokes. The effect is maintained for a long time; it causes regression of mental, intellectual and motor disorders, promotes regression of post-stroke dementia and significantly improves the quality of life, which makes it noticeably different from the conservative methods of treatment.