Aim. To ascertain a relationship between cholesterol content in circulating immune complexes (CIC) and plasm lipid peroxidation (LPO) in patients with ischemic heart disease (IHD). Materials and methods. Blood samples from 33 IHD patients 23 of which had a history of myocardial infarction and from 8 healthy subjects were examined for total cholesterol, high and low density lipoproteins cholesterol, CIC, the ability of blood serum to induce free radicals, superoxide dismutase. Results. A statistically significant positive correlation was found between CIC cholesterol level and content of free radicals while a negative correlation existed between superoxide dismutase activity and high density lipoprotein cholesterol level in blood plasm of healthy individuals and patients with IHD. After myocardial infarction an inversion of the above parameters was seen as a result of disorders in both antioxidant and immune systems. Conclusion. The level of both LPO and CIC cholesterol, their interaction are important atherogenic factors in development of IHD.