Infection of an intravenous pacemaker electrode developed in a 78-year-old man after multiple replacements and revisions of the pulse generator and the pacemaker lead. Spread of the infective process to the endocardium was followed by septicemia with Serratia marcescens and Staphyloccus epidermids. Failure of medical treatment and external traction on the pacemaker electrode led to thoracotomy and removal of the pacemaker electrode wires with the use of extracorporeal circulation. The tip of one of the pacemaker electrodes was found imbedded in the wall of the right ventricle and attached to the base of the tricuspid valve. Cultures from the endocardium removed with the electrode rendered the same organisms as cultured preoperatively. There has been no recurrence after 2 years following the removal of the infected electrodes. Although the problem described herein is not frequently found, radical treatment becomes necessary whenever infection and septicemia develop.