Since the introduction of the pulmonary artery catheter (PAC) in 1970 by Swan et al., various complications are recognized with the insertion and the use of Swan-Ganz catheter. We present two different cases with rare but life threatening complications which had been successfully managed. The first case is a carotid cannulation with an 8.5 Fr introducer sheath, in an attempt to insert a pulmonary catheter via the right internal jugular vein. Two weeks later, the patient was re-admitted to the hospital and when an arteriovenous fistulae (carotid artery-internal jugular vein) was diagnosed, he was treated surgically. The second case presents the rupture of the right atrium in the conjunction with the superior vena cava. This serious cardiac complication was developed during the floatation of the PAC and the lesion was repaired while the mitral valve replacement was in progress.