Background: The combination of left atrial appendage closure (LAAC) and catheter ablation (CA) in a single procedure is a safe and effective form of treatment for atrial fibrillation (AF). However, several findings have argued that LAAC might increase the risk of AF recurring. Therefore, this study investigated the impact of insufficient ablation on AF recurrence after the hybrid procedures of CA and LAAC. Methods: We reviewed 107 consecutive patients with AF who received the CA and LAAC hybrid procedures (combined group). In the case–control study, another 107 patients who underwent only CA (ablation group) were successfully matched using propensity score matching. After correcting the insufficient ablation, 107 consecutive patients were enrolled prospectively. During the follow-up period, postprocedural 24-hour monitor recordings and a portable electrocardiogram (ECG) monitoring device were used to detect AF recurrence. Transesophageal echocardiography was used to evaluate LAAC. Results: The combined group showed an increase in the risk of AF recurrence after 539.2 \pm 304.4 days of follow-up (29.9% vs. 15.9%, p 0.05). Interestingly, the duration of the procedure was not significantly prolonged when LAAC was added after CA in the combined group, while there was a higher number of ablating attempts, duration of ablation, and additional ablation in the ablation group for both radiofrequency and cryoballoon ablation. After correcting for the insufficient ablation, the corrected group showed a significant decrease in AF recurrence after 420.4 \pm 204.8 days of follow-up. Conclusions: Insufficient ablation is common when combining CA and LAAC and may lead to the recurrence of atrial fibrillation. It should be corrected intentionally by sufficient ablation of the pulmonary vein antrum and additional ablation. Clinical Trial Registration: The prospective study is a sub-study of our CAGEDAF study that has already been registered (ChiCTR2000039746).