•Freedom from composite endpoint at 3-years was high in HFrEF and HFpEF patients.•Smaller LV diastolic diameter was the sole predictor of LVEF normalization.•No recurrence after initial procedure was the sole predictor of shortening of the LV diastolic diameter. Heart failure (HF) promotes atrial fibrillation (AF) and AF worsens HF. This study aimed to investigate the long-term clinical outcomes after AF ablation in patients with HF. A total of 106 consecutive HF patients, including 51 (48.1%) with a reduced left ventricular ejection fraction (LVEF) (HFrEF) and 55 (51.9%) with a preserved LVEF (HFpEF), underwent AF ablation. All patients underwent successful pulmonary vein antrum isolation, and substrate modification was added in 38 (35.8%). The mean follow-up period was 32.4±18.6 months, and mean number of procedures was 1.4±0.5 per patient. Low-dose antiarrhythmic drugs were combined in 29 (27.3%) patients. Freedom from recurrent atrial arrhythmias (ATa), HF-related hospitalizations, and the composite endpoint (all-cause death, stroke, HF-related hospitalizations) at 3 years was 88.7%, 97.6%, and 97.6% in HFrEF patients, and 79.3%, 96.2%, and 91.8% in HFpEF patients, respectively. LVEF normalization (≥50%) was observed in 37 (72.5%) HFrEF patients post-ablation, and a smaller LV diastolic diameter (LVDd) was the sole predictor odds ratio (OR)=0.863; 95% confidence interval (CI)=0.779–0.955, p=0.005. Shortening of the LVDd (≥5mm) was observed in 16 (29.1%) HFpEF patients post-ablation, and no recurrence after the initial procedure was the sole predictor (OR=6.229; 95% CI=1.524–25.469, p=0.011). Catheter ablation of AF could be one of the important therapeutic options in the management of patients with HF combined with AF regardless of the type of HF.