In members of the families whose parents had atherosclerosis complicated by macrofocal myocardial infarction or stroke, the serum level of lipid peroxidation products was correlated to enzymatic activity of neutrophil and red blood cells oxidation-antioxidation. In persons with hereditary predisposition to atherosclerosis both with clinical signs of atherosclerosis and phenotypically healthy against the control group there was elevated content of plasma acylhydroperoxides and hypoactivity of neutrophil myeloperoxidase. Determination of lipid peroxidation products by malonic dealdehyde showed this parameter to be higher in members of the families of the study group and in those with cardiovascular disorders. For those whose parents had atherosclerosis versus control subjects there were no differences in the activity of superoxide dismutase, glutation peroxidase and catalase in the blood red cells. Shifts in lipid peroxidation and activity of blood myeloperoxidase are identical in type and may represent a pathogenetic ling in formation of hereditary predisposition to cardiovascular disorders of atherosclerotic origin, the detection of which becomes feasible in a subclinical period.