A certain degree of prosthesis oversizing (OS) is recommended for the SAPIEN 3 to achieve device success. However, an increase in OS may increase permanent pacemaker implantation (PPI) rates. We therefore investigated the influence of OS on device failure and PPI.A total of 804 patients were treated with SAPIEN 3 at 3 centers. Multislice computed tomography-derived OS was calculated and analyzed both as a continuous variable and categorized in 5% increments with -4% to 0% as reference.Device failure occurred in 8.8% of patients. Median OS was lower in patients with device failure vs those with device success (+4% vs +8%; P=.038). A nonlinear risk pattern was shown for OS with a significantly reduced device failure rate within 4% to +22% of OS. There was no case of paravalvular leakage II+ between +10% to +20% of OS. The overall PPI rate was 16.2% and the median OS was significantly larger in patients with PPI (PPI: +9% vs no PPI: +7%; P = .025), while implantation depth did not vary in patients with vs without PPI (6.9±1.7 mm vs 6.6±1.9 mm; P=.101). The risk of PPI increased with increasing OS and was highest in the 2 highest categories.An increase in OS reduces the risk for device failure but increases the risk for PPI. There was no ideal range of OS to minimize both device failure and PPI.