Background: The reasons of pacemaker replacement are end of life (EOL) of battery and lead failure. The incidence of lead failure is reported as 14.1���40%. We studied the clinical features and management of the patients with pacemaker replacement. This report describes our experience with pacemaker replacement including lead failures Methods: From August 1988 to May 2004, 671 pacemaker implantations were performed. Information included indication of replacement, lead status, model of pacemaker and lead, date of implant and failure, venous status, sign and clinical consequences at the time of pacemaker replacement, and how lead failures were managed. 100 pacemaker replacements were performed in our lab. Results: The lead failure was 15 cases (1 atrial lead, 14 ventricular leads), venous obstruction of previous lead implanted vein was 8 cases (6 cases in lead replacement group. vs. 2 cases in the only generator exchange group.). The clinical symptoms were dizziness, syncope, and dyspnea. The symptom occurrence rate was 32% in the regular follow-up patients, which is less than irregular follow-up patients (88%, p<0.05). The mean time to failure of lead failure was 5.4짹4.0 yrs. which is shorter than that of only generator exchange group (7.5짹2.0 yr, p<0.05). The signs of lead failure were capture failure in 2 patients, high threshold in 3, over/under sensing in 3. and impedance change in 7. In the lead failure, 5 lead failure was managed by replacement via the same venous access, 7 replacement via new access, and 3 data not collect. Conclusion : The higher rates of clinical symptoms and lead failure of the irregular follow group suggest that regular evaluation of pacemaker function is valuable. A venogram should be performed if a new lead is needed in the case of lead failure.