The implantable cardioverter-defibrillator (ICD) has been shown to decrease the risk of sudden cardiac death in patients when used for primary and secondary prevention. These devices are being used more frequently as indications for primary prevention broaden, and attention has become increasingly focused on complications caused by lead failure. A report using data from a large registry revealed that the cumulative incidence of lead malfunction that necessitated surgical revision of the ICD lead system was 2.5% over 5 years. A strategy to deal with failed leads by the implantation of new pace-sense leads or high-voltage leads resulted in a 20% malfunction recurrence rate at 5 years. Defibrillator leads have been termed the 'weakest link' in the ICD system. Further efforts from manufacturers, regulators, and implanting physicians are required to understand and address the causes of lead failure.