Acute coronary syndromes (unstable angina pectoris, acute myocardial infarction, sudden heart death) present an important part of cardiovascular and total morbidity and mortality. The common pathogenetic mechanism of them is the break of integrity of "stable" atherosclerotic plaque through fissure or rupture with following dynamic occlusion of coronary artery. In dynamic occlusion take part coronary vasoconstriction and dominant coronary thrombogenesis. Summary review of pathogenesis of coronary thrombosis aimed at origin of "unstable" atherosclerosis plaque, importance of vessel wall factors, rheologic factors and thrombocytes is presented in the paper. Morphologic and structural characteristics of "primary" atherosclerotic plaque and of coronary artery lesions in concrete acute coronary syndromes are described. From the point of view of clinical practice the authors draw attention to the basic importance of thrombin and residual thrombosis in acute coronary syndromes. Presented pathogenetic aspects of coronary thrombogenesis justify newer therapeutic approaches, which are in the phase of intensive research.