Single coronary artery is a rare congenital anomaly occurring in approximately 0.04% of the population. This entity can be diagnosed during life only by coronary angiography. Typical angina does not occur with single coronary artery in the absence of coexisting coronary artery disease or aortic stenosis. Among 874 patients who underwent diagnostic coronary angiography at Asan Medical Center. we have experienced a case of single coronary artery with significant atherosclerotic coronary artery disease which has been managed succesfully coronary angioplasty. We report this case of single coronary artery with a review of literature.