Although echocardiographic manifestations of Swan-Ganz catheters have received increasing attention, auscultatory sequelae have not previously been described. In the patient described in this report, insertion of a Swan-Ganz catheter resulted in a loud mid systolic click; removal of the catheter eliminated the click. Simultaneous phonoechocardiograms suggest that the click resulted from crisp contact of the catheter against the ventricular septum. Catheter momentum was enhanced by wide excursion and systemic pressures in the right ventricle; paradoxical motion of the septum during systole may have accentuated the force of its contact with the catheter.