Background: Nonenzymatic glycation of macromolecules, the formation of advanced glycation endproducts (AGEs), in various tissues has been known to enhance immunoinflammatory reaction and local oxidant stress in long standing diabetes. The accumulation of AGEs in blood and various tissues has been implicated in the development of the diabetic micro- and macrovascular complications. However, the potential role as a risk factor for coronary artery disease (CAD) and vascular events in diabetic patients remains unknown. Therefore, we investigated whether serum levels of AGEs are associated with the severity of CAD or the developement of acute coronary syndrome (ACS) in diabetic patients. Methods: The blood samples were collected from the diabetic patients with CAD (n=168) and without CAD (n=26). Subgroup analysis was performed for clinical diagnosis (111 pts with stable angina and 57 patients with ACS) and angiographical diagnosis (group of 1VD, 2VD and 3VD), respectively. The serum levels of AGEs were analyzed by fluororescent intensity method. Furthermore, multiple logistic regression was performed to determine whether serum levels of AGEs is an independent risk factor of ACS. Results: There was no significant difference of conventional risk factors between diabetic control, stable angina with diabetes and ACS with diabetes and no significant correlations between serum levels of AGEs and angiographical severity of CAD. Among the entire study population, there was significant difference of AGEs level between diabetic control/stable angina and ACS (157.5+25.1/157.3+27.2 vs 171.4+48.8 units/ml, p=0.04) The multiple logistic regression analysis showed that elevated AGEs(> 190 units/ml) was an independent risk factor of ACS in diabetic patients.(OR= 5.96: 2.07-17.15, p=0.001) Conclusion : AGEs (serum AGE level���190 units/ml) was an independent risk factor of coronary vascular events resulting in ACS in diabetic patients. Further investigations are required to evaluate the immunoinflammatory reaction in the vascular tissues.