Objective: To study the effect of vasonit on the structural/functional state of erythrocyte cytoplasmic membrane in patients with ischemic stroke (II) using atomic-power microscopy in vitro. Material and methods: We examined 45 patients with II. Patients of the main group (n=30) received vasonit and standard treatment, 15 patients of the comparison group received only standard treatment. To assess the severity of patient’s condition, we used the NIH stroke scale, modified Rankin scale, the Barthel index and the Rivermead Mobility index. Dried erythrocyte preparations were made to study erythrocyte cytoplasmic membrane. Scanning was performed using an atomic-power microscope manufactured by «SOLVER P47-Pro» (NT-MDT, Russia). Results and Conclusion: A statistically significant positive dynamics of neurological deficit and patient’s functional state was found in the 14th day of the study. A significant decrease in Young’s modulus value was identified in the main group that suggested the increase in the elasticity of erythrocyte cytoplasmic membrane.