A 51-yr-old man underwent mitral valve replacement and tricuspid valve repair due to mitral and tricuspid regurgitation under cardiopulmonary bypass. The pulmonary artery (PA) catheter was inserted easily via right internal jugular vein and functioned well until the end of surgery. The surgery was uneventful and patient's hemodynamics were stable both in the operating room and intensive care unit. All PA catheter functions were normal, but the balloon rupture was suspected because it was unable to obtain pulmonary capillary wedge pressure. On attempted removal of the PA catheter at the next day, considerable resistance was encountered and pulmonary artery tracing was dampened. A followed-up chest X-ray revealed the catheter to be in the right pulmonary artery without evidence of knotting. Suture related entrapment was suspected, and on reoperation, PA catheter was found to be sutured at the left atriotomy site. The PA catheter was removed under cardiopulmonary bypass and revealed a hole between proximal port and thermal filament.