The purpose of the investigation was to study peculiarities of autoimmune reactions against full-size tyrozyltRNA synthetase (TyrRS) and its individual modules in patients with systolic congestive heart failure (CHF) of different origin. The estimation of level of specific antibodies (AB) against full-size TyrRS and its individual N- and C-modules in blood sera of patients with cardiomegaly and systolic CHF of coronary (ischemic heart disease) and noncoro nary (dilated cardiomyopathy, DCM, and chronic myocarditis, ChM) origin was carried out by the ELISA method. Sera of 20 patients with DCM, 44 pts with ChM and 18 pts with CHF resulting from chronic ischemic heart disease and essential hypertension were studied. All patients had CHF IIА–IIB stage, NYHA II–III functional classes. The average index of left ventricular (LV) end-diastolic volume was 125.95±4.28 ml/m2, LV ejection fraction – 34.25±0.53%. All patients were treated with beta-blocker, inhibitor of angiotensin-converting enzyme, diuretic. Blood tests were performed only after clinical stabilization. Sera of 20 practically healthy donors (HD) were used as a control. Significant increase (by 20–25%) of anti-full-size TyrRS AB level was detected only in sera of patients with “noncoronary” CHF (DCM and ChM). This AB level in sera of patients with “coronary” CHF (ischemic heart disease) didn’t exceed the normal value. The increased level of specific anti-Cmodule of TyrRS AB was found in all groups of CHF patients, regardless of syndrome origin. These AB titers in all groups of CHF patients were significantly higher (by 19–28%) than in control group HD. At the same time significant elevation (by 21%) of specific anti-TyrRS N-module AB level was detected only in sera DCM patients.