Diabetes mellitus is an increasingly prevalent condition in the modern era. Coronary artery disease is the major cause of mortality in this population. Despite advances in the therapeutic modalities available for management of coronary artery disease, diabetic patients tend to have worse short and long term outcomes. Acute coronary syndrome in this patient population should be managed aggressively with antithrombotic and antiplatelet agents, as well as early mechanical reperfusion strategies. Diabetic patients presenting with acute coronary syndrome benefit from intensive glycemic control in the first 48 hours. Percutaneous coronary angioplasty using drug-eluting stents with concomitant glycoprotein IIb/IIIa inhibitors should be considered early in diabetic patients with single vessel and multivessel disease. Long-term preventive measures include aspirin, clopidogrel, statins and angiotensin- converting enzyme inhibitors.