Atrial fibrillation (AF) is the most frequent of all cardiac arrhythmias and it is associated with an increased risk of stroke, systemic embolism and heart failure. Patients with AF have a twofold increased risk of death and fivefold increased risk of stroke compared with those without AF. In patients with heart failure (HF), AF ablation improves left ventricular (LV) function over short- and long-term follow-ups, especially compared with medical treatment. Furthermore, AF ablation in HF patients relates to a significant improvement in quality of life, functional class and exercise tolerance, possibly related to the improvement in LV function and hemodynamic status of the patients. Finally, data showed that restoration of sinus rhythm in this setting of patients reduced the incidence of stroke and death. In this review, we reported all the major data regarding atrial fibrillation therapy in patients with heart failure.