Objective. To study microcirculation in patients with acute ischemic stroke (IS) using the method of laser Doppler fluorimetry (LDF). Material and methods. We examined 19 patients with acute carotid IS, including 12 patients who received thrombolytic therapy. The reference group included 22 patients with chronic cerebral ischemia without a history of IS. Computed and magnetic resonance tomography of the brain, ultrasound diagnosis of head and neck vessels, the study of the changes in neurological status, emotional sphere, cognitive functions and laboratory methods were used. Results. An index of total blood flow in the microcirculatory bed on the side of stroke was lower compared to that in patients with chronic cerebral ischemia. The study of parameters of microcirculatory bed regulation revealed an increase of blood inflow into the microcirculatory bed with the augmentation of the myogenic activity of arterioles and primarily the nutritional regimen of microhemocirculation. A decrease in the myogenic activity in the microcirculation system and nutritional direction of microhemodynamics were noted in patients with large IS. In some cases, non-nutritional regimen and/or venule congestion were observed. Conclusion. The study of the microcirculation system with the LDF method can be used as the method of early diagnosis of unfavorable variants of cerebral microcirculation that is necessary for outcome prognosis and its correction.