Atrial flutter is a reentrant tachycardia that originates in the right atrium. The wave front of atrial flutter travels craniocaudally along the anterolateral wall of the right atrium, surrounds the inferior vena cava, and crosses the region between this structure and the tricuspid ring before closing the. circuit after upward septal propagation. The area located between the tricuspid annulus and the inferior vena cava has been proposed as an ideal target for ablation because it appears to be an isthmus that is an obligatory route for closing the inferior part of the arrhythmia circuit. Various publications dealing with radiofrequency ablation of this tachycardia have dealt with different approaches, and a wide range of acute and chronic success rates have been reported. The main difficulty in interpreting the results of this series is the lack of a carefully defined patient selection, technique description, and follow‐up protocol. In almost all of these series it clearly appears that a significant number of late flutter recurrences occur in these patients, in addition to the emergence of previously unknown atrial fibrillation. Many recent reports, where ablation has been targeted at the inferior vena cava‐tricuspid annulus isthmus, have shown a high rate of acute, success. In our experience, the procedure seems to be facilitated by the use of extra large tip (8‐mm) ablation catheters that allow the use of higher power outputs. Careful mapping of the ablation site has shown that creation of complete bidirectional block at the isthmus is important for prevention of late recurrences. Further technological improvements should aim at developing energy delivery systems that allow controlled destruction of wide areas of the atrial myocardium. (J Interven Cardiol 1996;9: