Patients with diabetes mellitus (DM) and acute coronary syndromes (ACS) present a significantly higher risk of developing ischemic complications as compared to nondiabetic patients. Multiple mechanisms contribute to DM patients' enhanced prothrombotic status, including impaired fibrinolysis and coagulation, as well as endothelial and platelet dysfunction. Therefore, antithrombotic agents generally, and antiplatelet agents in particular, represent a logical secondary preventive strategy to reduce the risk of recurrent ischemic events in DM patients with ACS. However, DM patients often show attenuated responses to antiplatelet therapies for ACS patients. DM patients benefit from early coronary angiography and revascularization. Although randomized clinical trials have demonstrated that surgical revascularization is associated with an improved prognosis compared to percutaneous coronary intervention, a tailored revascularization strategy should be provided for each patient. The type of revascularization should be decided on the basis of SYNTAX score, surgical risk profile, and feasibility of total arterial revascularization in case of surgery. An accurate diagnosis and prompt treatment of hyperglycemia should also be provided for all patients. The present multidisciplinary document provides practical recommendations regarding diagnosis of DM and the management of hyperglycemia, from the acute phase to discharge. It is aimed at favoring early detection of hyperglycemia and identification of diabetic patients so as to provide adequate glucose control.