There have been controversies concerning the optimal target sites and approaches in radiofre-quency catheter ablation of common atrial flutter. We attempted high energy radiofrequencv catheter ab-lation targeting the isthmus between the inferior vena cava and tricuspid valve annulus (IVC-TV isthmus) with a super long (8 mm) tip electrode, and compared the efficacy of this anatomical approach with the electrophysiological approach targeting the posteroseptal right atrium posterior to the coronary sinus us-ing a standard 4-mm tip electrode. Atrial flutter was successfully ablated in 12 of 12 patients (100%) with-out recurrence with the anatomical approach, while, in 7 of 9 patients (64%) with 2 recurrences with the electrophysiological approach. In comparison of ablation data between the anatomical and electrophysi-ological approaches, there were significant differences in the mean number of application pulses (anatomical vs electrophysiological: 2.3 ± 0.8 vs 9.9 ± 6.4, P < 0.01), applied wattage (39 ± 12Wvs24 ± 6W.P < 0.01), applied energy per application (1.986 ± 426 / vs 659 ± 323 J. P < O.O1), fluoroscopic time (26 ± 11 min vs 74 ± 30 minutes, P < 0.01), and procedure time (59 ± 8 min vs 181 ± 53 min. P < 0.01). In conclusion, the anatomical approach is superior to the electrophysiological one with respect to proce-dure and radiation time, and linear ablation at the IVC-TV isthmus with an 8-wm tip electrode and high energy application is highly effective and safe.