Over the past 5 years, catheter ablation of atrial fibrillation (AF) has evolved from being an experimental procedure to one that is performed in most large medical centers throughout the world. The rapid and widespread acceptance of this procedure reflects encouraging reports of the safety and efficacy of a pulmonary vein (PV) approach, which has 70-80% efficacy and around a 5% risk of major complications. Currently three PV-based ablation strategies are employed for catheter ablation of AF, termed segmental PV isolation, circumferential PV ablation and circumferential PV isolation. Three main research activities are ongoing in the field of catheter ablation of AF. One aim is to better define the safety and efficacy of AF ablation using the three approaches listed. The second research focus is to improve safety and efficacy by the development of new mapping and ablation tools. And the third major area of research is the development of new strategies for AF ablation. It is highly likely during the next 5 years that catheter ablation of AF will become a routine and well-accepted treatment strategy for this common arrhythmia condition.