Uncontrolled hyperthyroidism is a risk factor of perioperative thyrotoxic crisis. We report a case of a 61-year-old woman with thyrotoxicosis diagnosed with unstable angina pectoris. She needed to have an early scheduled coronay artery bypass grafting surgery, because percutaneous intervention for the left main coronary artery in support of intra-aortic balloon pumping (IABP) resulted in failure. Tachycardia and hyperthermia were observed at admission to the ICU, and hemodynamic parameters suggested high-output heart failure. Preoperative management using antithyroid drug, inorganic iodine, corticosteroid and propranolol stabilized her hemodynamic condition, and then CABG was performed on ICU day 3. Intraoperative and postoperative use of landiolol, a short acting beta blocker, was useful for maintaining hemodynamic stability. Surgery was uneventfully completed and she was extubated on postoperative day 1 following IABP withdrawal. Appropriate preoperative management and perioperative use of the short acting beta blocker were useful for management of the patient with uncontrolled hyperthyroid state.