The American College of Cardiology and the American Heart Association (ACC/AHA) 2013 joint guidelines for the treatment of hypercholesterolemia expand the indications for statin therapy. This study was performed to estimate the numbers of diabetic patients indicated for statin therapy according to the Third Adult Treatment Panel (ATP-III) of the National Cholesterol Education Program guidelines and the new ACC/AHA guidelines in Korea. We analyzed the data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2010-2012. Patients with diabetes over 30 yr of age were analyzed by the two guidelines. Of the total 1,975 diabetic patients, only 377 (19.1%) were receiving drugs for dyslipidemia. Among 1,598 patients who had not taken any medications for dyslipidemia, 65.6% would be indicated for statin therapy according to the ATP-III guidelines. When we apply the new guidelines, 94.3% would be eligible for statin therapy. Among the total diabetic patients, the new guidelines, compared with the ATP-III guidelines, increase the number eligible for statin therapy from 53.1% to 76.2%. The new guidelines would increase the indication for statin therapy for most diabetic patients. At present, many diabetic patients do not receive appropriate statin therapy. Therefore efforts should be made to develop the Korean guidelines and to ensure that more diabetic patients receive appropriate statin therapy.