Placement of a pulmonary artery catheter for hemodynamic monitoring in the operating room or intensive care unit is very useful, but this is associated with various complications. They are rupture of the pulmonary artery, pneumothorax, hemothorax, thromboembolism, hemoptysis, arrythmia, valvular damage, sepsis, rupture of the balloon, entrapment or knotting of the catheter and so on. We experienced a case of perforation of the superior vena cava that was caused by a pulmonary artery catheter during liver transplantation. We diagnosed hemothorax during the operation, and we recognized the perforation by performing thoracoscopy. The perforation site was sutured successfully and there were no more problems.