Catheter ablation has evolved over the past two decades to become first-line therapy for many cardiac arrhythmias. Multiple advances in the technology and understanding of radiofrequency ablation have allowed this technique to blossom into one of the most powerful therapeutic tools available to the electrophysiologist, and have opened a new chapter in the diagnosis and management of clinical arrhythmias. Catheter ablation often eliminates the need for chronic drug therapy and can result in significant long-term cost savings. As catheter technology continues to improve, and newer, more effective energy delivery systems are developed, the applicability of catheter-based therapy will continue to expand. This review addresses some of the more commonly encountered clinical arrhythmias and the recent developments in the treatment of these arrhythmias from a catheter-based standpoint.