Cerebrovascular diseases including stroke are an important problem of public health. Stroke development depends on external factors and individual genetic specificity of patient. Excessive NO production by inducible NO-synthase (iNOS) damages brain tissue at various stages of the disease. The goal of this work was to study the role of 4 polymorphic variants of gene of inducible NO-synthase iNOS (-2447C/G, -1659C/T, -0,7(OTTA)n I/D, S608L (150C/T)) in brain infarction in patients with acute ischemic stroke. A statistically significant correlation between S608L (150C/T) polymorphism and infarction dynamics was observed during days 1-3 and 7-21 after infarction. These parameters correlated with neurological status estimated using the Orgogozo scale during days 1-7 of the disease development. It was demonstrated that genotype N150N was associated with ischemic focus propagation regardless of its volume and neurological status by Orgogozo scale in patients with acute stroke. It was also observed that genotype N150N had effect on ischemic damage during days 1-3 in case of low initial volume.