BACKGROUND: The radiofrequency catheter ablation (RFCA) has been a standard treatment modality for paroxysmal supraventricular tachycardia (PSVT). With successful RFCA of PSVT, a few recurrence has been reported. However, the reports of clinical features and factors associated with recurrence are limited. The present study was performed to evaluate clinical features and factors associated with recurrence after RFCA for PSVT. METHODS: We analyzed clinical and RFCA data 2326 patients with structurally normal heart who had undergone successful RFCA for PSVT (atrioventricular nodal reentrant tachycardia; AVNRT, atrioventricular reentrant tachycardia; AVRT, WPW syndrome) between 1995 and June 2005, retrospectively.RESULTS: Total 948 patients of AVNRT, 1378 patients of AVRT and 638 patients of WPW syndrome were involved. Ten patients in AVNRT group, 38 patients in AVRT group and 34 patients in WPW syndrome group had documented PSVT re-attack and had re-electrophysiology study In 10 patients of AVNRT recur group, 2 patients had concealed bypass tract (CBT) and other 8 patients (0.84%) had recurrence of AVNRT.In 38 patients of AVRT recur group, 1 had atrial tachycardia, 1 had AVNRT, 3 patients had AVRT with another bypass tract and 33 patients (4.45%) had local recurrence (2 had broad band type). In 34 patients of WPW syndrome recur group, 1 had atrial tachycardia and 4 had AVRT with another CBT. Twenty nine patients (4.55 %) of WPW patients had re-attack of PSVT with same bypass tract (one had broad band type and 8 had only VA retrograde conduction). The ratio of right side bypass tract was higher in recurred AVRT (14.6 % vs. 27.0 %, p=0.06) and WPW syndrome (36.8% vs. 59.4 %, p= 0.014).There was no difference in age, sex, delivered RF time, the mean RF energy, the mean local temperature and the number of booster RF energy delivery between recur and no-recur group in all three PSVT group. CONCLUSIONS: The recurrence rate after successful RFCA of AVNRT was lower than that of AVRT and WPW syndrome. Right side bypass tract has larger tendency of recurrence than left side bypass tract. Key word: paroxysmal supraventricular tachycardia, radiofrequency catheter ablation, recurrence