The combination of diabetes mellitus and coronary artery disease (CAD) constitutes an aggressive disease characterized biologically by chronic inflammatory, proliferative and pro-thrombotic situation. In the "diabetic patient" the increased frequency and gravity of simultaneous myocardial infarction and the deterioration of congestive heart failure contribute to the inevitable unfavourable final result. Diabetes accelerates the natural course of atherosclerosis and involves a great number of coronary vessels with more diffuse atherosclerotic lesions. Moreover, the risks of plaque ulceration and thrombosis have been shown to be considerably higher in diabetic patients. The treatment should be also aggressive and be based on the combined treatment of CAD and the effective regulation of glucose levels. The decision of revascularization in the diabetic patient should be posed relatively earlier. The surgical choice of revascularization seems to be advantageous over the interventional, with better early and late results.