Ebstein's anomaly is highly associated with atrioventricular reciprocating tachycardia (AVRT) due to an atrioventricular accessory pathway (AP). This case report describes a case of a 30-year-old man with Ebstein's anomaly who had been suffering from recurrent palpitation caused by AVRT due to the right-sided AP. Conventional mapping technique failed to ablate his AP successfully. In baseline electrophysiological study, orthodromic AVRT with a right posterior AP were induced. The AP was mapped using an electroanatomic mapping system. RF current was successfully delivered at the posterior site. RFCA using an electroanatomic mapping system seems to be useful for A VRT patients in Ebstein's anomaly.