A 47-year-old woman was scheduled for mitral valvoplasty. Before induction of anesthesia, a pulmonary artery catheter (PAC) was placed via right internal jugular vein. Central venous pressure or right atrial pressure was traced until about 60 cm of PAC insertion and right ventricular pressure curve appeared without arrhythmias. We withdrew and advanced the catheter several times, but pressure tracing showed the same pattern. And we could not obtain the pulmonary artery pressure. We decided to leave the PAC in the right ventricle. No ventricular arrhythmia was detected. Postoperative chest x-ray revealed that PAC traveled through inferior vena cava and looped in the hepatic vein with the tip of the catheter in the right ventricle. Under fluoroscopic guidance, PAC was inserted to the pulmonary artery. No sign of hepatic vein obstruction was detected.