The neuropsychological examination was carried out in 18 men (study group), mean age 59.7 +/- 6.6 years, before and after aorto-coronary bypass. The neuropsychological tests were carried out 2-3 days before operation and 14-16 days after it. 12 non-operated men with coronary artery disease, mean age 60.0 +/- 6.7 years, were studied as a control group. In control group the neuropsychological tests were conducted with a 16-19 day interval. The tests examined short-term verbal and visual memory, semantic memory. At statistical analysis of the results the mean values and confidential intervals were calculated allowing for Student's coefficient. In control group at consecutive tests the negative dynamics of the results was not revealed. The comparison of the tests results in the study group patients before and after operation revealed the a decrease of neuropsychological parameters by 20-40% on the average irrespective of material modality. Features of cognitive changes revealed in early postoperative period, testifies to diencephalic type of the disorders.