Diabetes mellitus is associated with an increased prevalence of and morbidity from coronary artery disease, which is present in at least 25% of diabetic patients. Diabetes mellitus is a risk factor for recurrent cardiovascular events after myocardial infarction and after percutaneous coronary intervention procedures or coronary artery bypass surgery. Less than half of the increase in cardiovascular events with diabetes mellitus is accounted for by the presence of traditional cardiac risk factors such as hypertension, hypercholesterolemia, and hypertriglyceridemia. Vascular inflammation reflected by increased levels of high-sensitivity C-reactive protein, endothelial dysfunction associated with hyperglycemia and hyperinsulinemia, impaired fibrinolysis mediated by hyperinsulinemia, and increased platelet aggregation are now recognized as promoting the development of arteriosclerosis in diabetic patients. These factors may be present long before a diagnosis of diabetes mellitus is established. Platelets in diabetic subjects appear to be in an activated state even in the absence of vascular injury, as evidenced by greater expression of the fibrinogen-binding glycoprotein IIb/IIIa receptor, which constitutes the final common pathway of platelet activation and allows for crosslinking of individual platelets by fibrinogen molecules and formation of thrombus. Platelet inhibition with intravenous glycoprotein IIb/IIIa inhibitors has been shown to reduce morbidity and mortality in patients undergoing percutaneous coronary intervention for acute coronary syndromes, and diabetic patients appear to derive an even greater relative benefit from this treatment. The ACC/AHA 2002 guidelines for the management of acute coronary syndromes recommend the use of abciximab in diabetic patients undergoing stent implantation.