A clinical-immunologic study of 133 patients was carried out to elucidate the status of the T- and B-immune systems in atherosclerotic dyscirculatory encephalopathy (ADE) in the acute period of cerebral infarction and hemorrhagic stroke. A similar pattern of elevation in humoral and tissue immunity, with quantitative fluctuations in the intensity of individual parameters in various dyscirculatory disorders, was found. The changes indicate that cerebral stroke develops in the body already sensitized in the prestroke period and its development involves the central and peripheric links of the immune system.