Diabetes mellitus (DM) is a worldwide epidemic. Its prevalence is rapidly increasing in both developing and developed countries. Coronary heart disease (CHD) is highly prevalent and is the major cause of morbidity and mortality in diabetic patients. The purpose of this review is to assess the clinical impact of recent advances in the epidemiology, prevention, and management of CHD in diabetic patients. A systematic review of publications in this area, referenced in MEDLINE in the past 5 years (2000 to 2005), was undertaken. Patients with CHD and prediabetic states should undergo lifestyle modifications aimed at preventing DM. Pharmacological prevention of DM is also promising but requires further study. In patients with CHD and DM, routine use of aspirin and an angiotensin-converting enzyme inhibitor (ACE-I)--unless contraindicated or not tolerated-and strict glycemic, blood pressure, and lipid control are strongly recommended. The targets for secondary prevention in these patients are relatively well defined, but the strategies to achieve them vary and must be individualized. Intense insulin therapy might be needed for glycemic control, and high-dose statin therapy might be needed for lipid control. For blood pressure control, ACE-Is and angiotensin receptor blockers are considered as first-line therapy. Noncompliance, particularly with lifestyle measures, and underprescription of evidence-based therapies remain important unsolved problems.