The relationship between the content of serum hormones (thyrotrophic hormone, thyroxin, dehydroepiandrosterone (DHEA), DHEA sulfate, prolactin) and cognitive impairment at the acute phase of ischemic stroke in the 1st, 7th and 21st day was investigated. There was the correlation between the hormone concentrations and severity of cognitive impairment. This finding supports the role of the hormones in cognitive functioning and their impairment in the acute phase of stroke. The lack of the hormones was mostly expressed in the group with severe cognitive impairment. The study of the hormonal pattern of cognitive regulation allowed to isolate the key biochemical pattern, i.e. the decrease in DHEA concentration, during the acute phase of stroke in the presence of marked cognitive deficit.