The purpose of the study was to investigate and evaluate the data of hematological studies in women and men with ischemic heart disease in critical condition. Materials and methods. The results of examination of 14 patients with ischemic heart disease in critical condition, who will be hospitalized for approximately the same period of time in the intensive care unit of the cardiology department of the Municipal Non-Profit Enterprise of Kharkiv City Council "Regional Clinical Hospital" were included in the study. The patients included 7 women and 7 men aged 38 to 60 years who were diagnosed with acute myocardial infarction at the clinic. Laboratory tests were performed at the time of hospitalization and after 3–4 consecutive days in the dynamics of treatment. Morphological evaluation of blood cells in a blood smear and quantitative indicators were included in hematological examination and were determined on a hematological analyzer ABX MICROS 60 OT (France). Results and discussion. The study found that women had an increase in white blood cell count, hemoglobin concentration an average and mean erythrocyte hemoglobin increases at the time of hospitalization. Increase in the number of leukocytes, decrease in hemoglobin and erythrocytes were found in men. On the dynamics of treatment for 3–4 days, the number of leukocytes in women decreased by almost 1.4 times compared to the data time of hospitalization, while in men — only by 1.02 time, 4 out of 7 men even had an increase in leukocytes. The number of erythrocytes, the concentration of hemoglobin in females has changed a lot, and the MCN indicator has dropped to the same level. The number of erythrocytes and hemoglobin concentration almost did not change in men. Conclusion. In women and men with ischemic heart disease in a critical condition some differences in hematological parameters were noted. It must be taken into account based on the principles of 4P therapy. Inflammation, according to leukocytosis, was higher in women at the time of hospitalization, but after treatment the reduction was more significant than in men. The numbers of erythrocytes, hemoglobin concentration, erythrocyte index of mean erythrocyte hemoglobin were slightly higher in women than in men. These indicators were mostly reduced in men. Received results show that an increase in procoagulant status was more characteristic for women, and the development of an anemic state was more typical for men. On days 3–4, complete recovery of hematological parameters have not yet occurred, the exception was a slight decrease in the number of leukocytes. This indicates a decrease in the intensity of inflammation. Prospects of further researches. The obtained results of hematological studies of critically condition of patients with ischemic heart disease confirm the importance of laboratory tests for the timely identification of the risk of complications and monitoring the state and prognosis of the disease in men and women