Between the pro- and antiinflammatory components of the immune system there is a dynamic balance, violation of which is an important mechanism of development of many pathological states, in particular, cardiac insufficiency. The purpose of the work was a study of secretion of cytokines by mononuclears in patients under myocardial infarction, uncomplicated (1 group) and complicated (2 group) acute cardiac insufficiency, and determination of balance between pro-(TNF-alpha, IL-6, IL-8) and antiinflammatory (1L-10) factors in development of acute cardiac insufficiency in patients with myocardial infarction. The results indicate that in patients of group 1 there is initially a high level of both proinflammatory and antiinflammatory cytokines. After 10 days, we observed a decline in the IL-6 level and an increase in the TNF-alpha and IL-10 levels. In patients of group 2 we observed initially high levels of TNF-alpha and IL-6 and a reduced levels of IL-8 and 1L-10, as compared to patients of group 1. In dynamics of supervision of this group, further increase of all proinflammatory cytokines and a decline of IL-10 was registered. Balance between the pro- and antiinflammatory cytokines reflects the index of inflammatory activity, determined by formula (TNFalpha+IL-6+IL-8)/IL-10 and testifying that in patients of group 1 in the dynamics of treatment there is normalization of cytokin's balance, accompanied by decline of the index, while in patients of group 2 the index rose at 10th day.