Atrial fibrillation (AF) is the most common clinically important cardiac arrhythmia. It is an important cause of stroke, contributes to the burden of heart failure and is a major contributor to health expenditure. Percutaneous catheter ablation is superior to medical therapy in reducing AF recurrences. It has an important role in treatment of patients with failed drug therapy. Successful catheter ablation improves left ventricular function in patients with heart failure. In addition, it may be appropriate for selected highly symptomatic patients as first line therapy. Catheter ablation for AF has been shown in randomised trials to reduce hospital admissions and improve quality of life. There is evidence from registry data to suggest it reduces the risk of stroke and improves mortality. Cost effectiveness has been demonstrated by modelling studies in both Europe and the United States.