This review article summarizes the existing literature on the current state of the problem of diabetes mellitus and acute coronary syndromes. In particular, the issues are analyzed related to the etiology, epidemiology, main pathophysiological features, classification of acute coronary syndromes, acute coronary syndromes without persistent ST-segment elevation on the electrocardiogram, acute coronary syndromes with ST-segment elevation, non-atherosclerotic causes of acute coronary syndrome, laboratory and instrumental diagnostic tests. Issues were analyzed related to the main approaches to the treatment of acute coronary syndromes, management of patients with diabetes mellitus and acute coronary syndromes, recommendations for secondary prevention. Initial treatment with corticosteroids includes acetylsalicylic acid, bolus heparin and intravenous heparin infusion (in the absence of contraindications). Antiplatelet therapy with ticagrelor or clopidogrel is also recommended. Pain is controlled using morphine/fentanyl and oxygen in case of hypoxia. Nitroglycerin can also be used sublingually or by infusion to relieve pain. Continuous monitoring of myocardial activity for arrhythmia is required. The choice of reperfusion strategy in patients with diabetes mellitus should be based on many factors, including assessment of clinical status (hemodynamic/electrical instability, prolonged ischemia), complications of chronic coronary syndrome, ischemic load, echocardiography, assessment of left ventricular function and any other comorbidities. In addition, various methods for assessing coronary artery disease and predicting mortality due to surgery are needed to make a final decision. Advances in the sensitivity of cardiac biomarkers and the use of risk assessment tools now enable rapid diagnosis within a few hours of symptom onset. Advances in the invasive management and drug therapy have resulted in improved clinical outcomes with resultant decline in mortality associated with acute coronary syndrome.