Aim. To study the clinical features of the course of acute coronary syndrome (ACS) in elderly patients with chronic obstructive pulmonary disease (COPD).Materials and methods. The study included 78 patients with ACS: 43 patients with ACS and COPD (group 1) and 35 patients with ACS without COPD (group 2). All patients underwent comprehensive clinical, instrumental, and laboratory examinations.Results. Among the risk factors for cardiovascular diseases (CVD), the most significant contributors to the development of ACS in patients with COPD were smoking, arterial hypertension, and elevated levels of C-reactive protein (CRP). Patients with ACS and COPD more frequently had non- ST-segment elevation myocardial infarction (NSTEMI). For patients with comorbid pathology, more pronounced changes in the coronary arteries were characteristic due to an increase in the total number of stenoses (p=0.02), hemodynamically significant stenosis (p=0.01), occlusions and critical stenoses (p=0.02), and extensive stenoses (p=0.04). Group 1 patients, compared to group 2, had hemodynamically significant stenosis located in the proximal (p=0.04) and distal (p=0.02) segments of the coronary arteries, as well as in second-order branches (p=0.02). No significant differences were found between the groups in the number of stenoses of the left main coronary artery and the middle segments of the major coronary arteries.Conclusion. In elderly patients with COPD, ACS development was more often preceded by angina symptoms and atypical myocardial infarction presentations, with NSTEMI predominating in the myocardial infarction structure. The main CVD risk factors in COPD patients were smoking, arterial hypertension, and elevated CRP levels. Atherosclerotic coronary artery disease in ACS patients with COPD was characterized by multivessel disease, predominance of middle and distal coronary artery stenosis. A significant feature of coronary artery disease in comorbid elderly patients was the increased total number of stenoses and the number of extensive stenoses.