A 56-year old female who had an atrial septal defect with tricuspid regurgitation received a patch repair and tricuspid annuloplasty. During weaning from cardiopulmonary bypass (CPB), bright red blood filled the endotracheal tube and breathing circuit. We suctioned the blood through the endotracheal tube. The bleeding was massive (about 400 ml) but the airway could be cleared with endotracheal suction. We irrigated endotracheal tube with normal saline with phenylephrine. The weaning of CPB was done and protamine was administered. The bleeding ceased when protamine was administered. Weaning from CPB was accomplished uneventfully. We found a little bleeding in the right main stem bronchus by flexible bronchoscopy but did not do any more procedures. In the intensive care unit, the patient had stable vital signs and good respiratory function. The patient was extubated without any problems at postoperative 1 day and transferred to ward without any complications.