Objective To study the clinical efficacy of catheter ablation for paroxysmal atrial fibrillation (AF) in patients with a permanent pacemaker (PM) for sick sinus syndrome (SSS). Methods Our prospectively established database of patients who underwent circumferential pulmonary vein (PV) ablation for paroxysmal AF was retrospectively reviewed. A total of 41 patients with a permanent PM for the treatment of SSS (SSS+PM group) and 123 age- and gender-matched control subjects (on a 1: 3 basis) without SSS or a permanent PM (no-SSS+no-PM group) were included in this study. AF recurrence was defined as the occurrence of confirmed atrial tachyarrhythmia lasting more than 30 seconds beyond three months after catheter ablation in the absence of any antiarrhythmic treatment. Results During a mean follow-up period of 18.3 +/- 10.6 months (range 3-30 months), 50 patients (30.5%) developed recurrence of AF. The recurrence rate was higher in the SSS+PM group than in the no-SSS+no-PM group (43.9% vs. 26.3%, p=0.011). A Cox regression analysis adjusted for age, valvular heart disease, left atrial (LA) diameter and PV isolation identified only SSS and the use of a PM together as an independent predictor of recurrence of AF (hazard ratio 2.02, 95% confidence interval 1.10-3.69, p=0.023). Conclusion Patients with a permanent PM for SSS are at an increased risk of recurrence of AF after catheter ablation.