Introduction/Aim. Atherosclerosis presents a serial of highly specific cellular and molecular responses, and could be described as inflammatory diseases. Accordingly, for development of acute myocardial infarction (AMI), structure and vulnerability of atherosclerotic plaque are more important than the extent of stenosis of infarct-related artery. Consequently, inflammation and atherosclerosis and its complications are in good correlation. C-reactive protein (CRP) as nonspecific inflammatory marker, has prognostic significance in coronary artery diseases. The aim of this study was to establish the correlation between inflammatory response expressed as levels of CRP and fibrinogen in serum and extent of coronary artery stenosis. Methods. Study included 35 patients with acute myocardial infarction, as the first manifestation of coronary artery disease, which were treated with thrombolytic therapy according to the guidelines. All the patient had a reperfusion. The patients with acute or chronic inflammatory diseases, an increased value of sedimentation, fibrinogen, CK ?190 U/L, early and late complications of AMI were excluded. CRP was measured on admission, after 24, 48 and 72 hrs, and 21 days latter, while fibriogen only on admission. Results. All the patients underwent coronary angiography, and were divided into two groups: the group 1 (23 patients), with significant stenosis of infarct-related artery (stenosis ? 75%), and the group 2 (13 patients) without significant stenosis (< 75%). Mean value of CRP serum level on admission in the group 1 was 4.4 mg/L, and in the group 2 7.2 mg/L (p < 0.001). The mean value of fibrinogen on admission in the group 1 was 2.7 g/L, and in the group 2 3.0 g/L (p < 0.001). The mean CRP value after 48 hrs in the group 1 was 21.7 mg/L, and in the group 2 42.4 mg/L. (p < 0.001). After three weeks, the mean CRP value was 4 mg/L in the group 1 and 5.5 mg/L in the group 2 (p < 0.001). There was no significant difference between the groups 1 and 2 related to gender, age, localization of AMI, CK, EF value, and risk factors for coronary artery disease. Conclusion. The patients with nonsignificant stenosis of infarct-related artery had increased inflammtory responses according to the CRP value, as a result of inflammatory process in atherosclerotic plaque and/or enhanced individual reactivity. nema