The implantation of permanent pacemakers often gives rise to complications. Migration of leads, an unusual complication, occurred in two of our patients with epicardial pacemakers. In one case lead fracture and subsequent displacement due to heart action occurred after an automobile accident. In the second case looping and migration of the wire occurred within a day after implantation although the lead continued to function properly for six months. The probable cause of migration in this patient was excess slack.