The effect of acute cold stress on changes in the content of hematopoietic stem cells (CD34iMNC-cells), lymphocytes and granulocytes in the central and peripheral organs of the immune system of mice was studied. It was shown that 24 hours after the stress response, the number of CD34iMNC cells in the bone marrow decreased significantly by 13% and in the spleen by 45%. At the same time, the content of bone marrow cells decreased by 21.9%. Also, in the blood, the amount of reticulocytes was significantly reduced by 62.5%. All this together proves the inhibition of the stress of bone marrow hematopoiesis. Against this backdrop, there was a significant increase in the number of white blood cells in the blood of 31.3% and can be considered as a typical stress reaction. Significant was the reduction of the content of thymus cells by 76.1% and the spleen by 53.4% with an increase in apoptosis among thymocytes 8.7 times, and among splenocytes by 2 times. The number of thymocytes in the G0 / G1 phases significantly increased, and in the phase S and G2 / M + S significantly decreased. The obtained results indicate that the development of acute cold stress has led to a decrease in the content of CD34iMNC cells in the bone marrow and spleen, as well as in the bone marrow, thymus and spleen cell division, this is probably due to the redistribution and apoptosis of certain cells, which should significantly change the course of immunological processes. The results can be used to create an experimental model for studying immunobiological processes during short-term cold stress in order to develop methods for improving the efficiency of regeneration of the immune system during stress reactions.