We report a patient undergoing redo cardiac surgery for combined replacement of the aortic and mitral valves. During the course of the operation, a Swan-Ganz catheter - positioned preoperatively - was accidentally fixed to the wall of the pulmonary artery. As this did not interfere with cardiac output measurement or the pulmonary artery pressure wave form, the fixation was not noticed until an attempt was made to remove the catheter. Fluoroscopy revealed both the catheter's immobility and the location of the suture fixation. The patient required a sternotomy to remove the catheter. In order to avoid this complication, the indications for pulmonary artery catheters during cardiac surgery should be carefully considered. If catheters are inserted, their mobility should by all means be ensured before the chest is closed.