Over the past 12 years, catheter ablation of atrial fibrillation (AF) has emerged from being a novel, largely unproven procedure to its role today as a very commonly performed procedure for treatment of patients with symptomatic AF.1–4 In fact, catheter ablation of AF has become one of the most commonly performed catheter ablation procedures at most large medical centers throughout the world. The objective of the present report is to provide a state-of-the-art review of the techniques, outcomes, and complications of catheter ablation of AF. Three main topic areas will be discussed. First, I will review the current approaches for and outcomes of AF ablation. Second, I will identify and briefly review areas in the field of AF ablation about which less is known and that remain active areas for research. Third, I will briefly review the current status of a number of emerging technologies, approaches, and tools that are being developed with the aim of improving the outcomes of AF ablation. Finally, I will conclude by sharing with you my perspective on the indications for AF ablation. It is now widely recognized that circumferential ablation of the pulmonary veins (PVs) with the goal of obtaining electric isolation of the PVs is the cornerstone for most AF ablation procedures.1 This ablation technique involves delivering a series of point-by-point radiofrequency lesions that encircle the 2 left and 2 right PVs either by creating a single circumferential lesion around the 2 right PVs and another around the 2 left PVs or by including lesions between the ipsilateral PVs, resulting in a figure 8 lesion set (Figures 1A and 1B). Electric isolation of the PVs is most commonly confirmed by use of a circular multipolar electrode catheter (Figure 2). Irrigated radiofrequency ablation catheters, used in conjunction with …