With the introduction of the DES, the angiographic rates of restenosis have decreased dramatically but less prominently in diabetic patients. Even in the era of DES, diabetes remains a significant predictor of coronary restenosis especially in cases of small baseline and post PCI vessel size, longer stent length, current smokers, and high level of CRP. Restenosis remains a main clinical and angiographic concern after DES implantation especially in diabetic patients. Diabetes has been known as a major risk factor for in-stent restenosis after DES implantation.