INTRODUCTION: Noise oversensing encountered in patients with Abbott Tendril leads in our hospital triggered an internal investigation. METHODS: We retrospectively analyzed patients with a Tendril lead model 1688, 1788, 1888, and 2088. Most leads were connected to Abbott generators. To exclude a primary generator issue as the cause of noise oversensing, we enrolled a cohort of patients in whom Medtronic CapSureFix leads model 4076 and 5076 were prospectively connected to similar Abbott generators. RESULTS: A total of 1063 Tendril leads were implanted in 869 patients. Noise was encountered in 66 leads (6.2%) during a follow-up of 3.9 years. Most affected leads had normal impedance and only a few of these patients were symptomatic. Reprogramming was attempted in 44 of 66 (67%), and reduced oversensing in 34 of 44 (77%) of these patients. Seventeen malfunctioning leads (1.5%) were replaced, including 16 of 66 (24%) of those with noise. Of the four leads with noise extracted and returned to the manufacturer, lead to device abrasion was identified in two and inner insulation breach in one. None of the 145 Medtronic CapSureFix leads connected to Abbott generators had noise during a follow-up of 3.6 years. CONCLUSION: Noise oversensing was relatively common in Tendril leads, but was not detected in Medtronic leads despite connecting to Abbott generators. Although the majority of the affected leads did not show abnormal impedance, outer or inner insulation breach was identified in three of the four returned leads. As patients with affected leads are generally asymptomatic, most of them can be managed conservatively.