There is a clinical dilemma in the treatment of patients with hypothyroidism and coronary artery disease; excess thyroid hormone administration may exacerbate anginal symptoms, and yet inadequate thyroid replacement may induce congestive heart failure. A case of successful coronary artery bypass grafting in a patient with angina pectoris and hypothyroidism is described in this paper. A 55 year-old woman with this complication initially received thyroid replacement therapy under strict monitoring. Forty days after the start of they thyroid replacement therapy, serum levels of thyroid hormone had reached the normal range, and then coronary artery bypass grafting was successfully performed. She recovered without any complications, and is now free from chest pain in spite of thyroid replacement therapy.