A 40-year-old patient with moderate factor IX deficiency (Christmas disease) underwent quadruple saphenous vein coronary bypass grafts for angina and severe coronary atherosclerosis involving the left and right main, left anterior descending, and circumflex coronary arteries. Excessive bleeding was prevented by infusion of factor IX concentrates during and after the operation. The surgical procedure and total body perfusion were carried out in the same manner as in patients without a hemorrhagic disorder. The patient was discharged after 13 days of hospitalization. He is doing well at the time of this publication and has returned to work.