This review enlightens the application issues of the novel CARTO electroanatomic mapping system (Biosense Webster, Diamond Bar, CA, USA) in both research and clinical electrophysiology.It is a very useful tool in catheter ablation procedures in patients with sustained atrial tachycardias, macroreentrant atrial arrhythmias after surgical correction of congenital heart disease, and ventricular tachycardia in the setting of previous myocardial infarction or other structural heart disease. It can also be useful in other types of arrhythmias, including isthmus dependent atrial flutter and idiopathic ventricular tachycardia, by guiding the ablation procedure and limiting fluoroscopy. The major drawbacks for more widespread use of electroanatomic mapping at present time include the inability to map nonsustained arrhythmias and the associated high costs of the mapping system.