Although intravenous thrombosis frequently complicates placement of transvenous endocardial leads in patients with permanent pacemakers, clinical manifestations of upper extremity thrombosis are uncommon. Most, including upper extremity edema, cervical venous engorgement, and even superior vena cava syndrome, can be successfully managed with conservative therapy. In the patient described in the present report, clinical manifestations of pacemaker-electrode thrombosis were neither mild nor responsive to conservative therapies: in this patient, pacemaker-electrode thrombosis ultimately required amputation of the right upper extremity. Complications of the magnitude described in this patient emphasize the need for continual review of the indications for pacemaker therapy as understanding of the risk-benefit ratio of this procedure broadens.