BACKGROUND: Atrial flutter is a common arrhythmia for which no entirely satisfactory treatment is available. Despite the growing number of antiarrhythmic agents available for arrhythmia prophylaxis many patients are either intolerant of drug treatment or achieve inadequate relief from their symptoms. Recently, catheter ablation using radiofrequency energy has been used to result in high success rate for immediate prevention of atrial flutter but significant recurrence rate. We report our initial experience on radiofrequency cather ablation(RFCA) of atrial flutter in 8 patients. METHODS: The electrophysiologic approach guided by the earliest artial activation was used in the first patient and then anatomically guided approach in the remaining patients. The end point of RFCA was both demonstration of conduction block across the linear lesion at the atrial isthmus between the inferior vena cava and the tricuspid ring and noninducibility of atrial flutter with atrial burst pacing and extrastimulation up to 3 during isoproterenol infusion. RESULTS: Eight consecutive patients underwent RFCA.All were male and mean age was 53+/-22 years. Initial success was achieved in 7 patients(88%). During the follow-up period of 4+/-2.3 months, early sympomatic recurrence occurred in 2/7 patients(29%) within 1 month after initial success and the second ablation procedure was successfully performed in one patient. Overall success rate at the end of the follow-up period was 6/8(75%). there were no serious complications during and after the procedure. CONCLUSION: 1) radiofrequency catheter ablation is safe and highly effective treatment modality for prevention of atrial flutter. 2) Demonstration of conduction block across the lesion at the atrial isthmus should be achieved as an endpoint.