An abnormal corrected QT (QTc) interval is associated with the development of atrial fibrillation (AF). It is unclear whether QTc interval is a marker of arrhythmia recurrence after radiofrequency catheter ablation (RFCA) in patients with AF. This study sought to determine the relationship between abnormal QTc interval and the recurrence after RFCA in hypertensive patients with paroxysmal AF. Two hundred and forty-two hypertensive patients with paroxysmal AF who underwent first time RFCA were retrospectively evaluated. Baseline data and QTc before the procedure were collected. Ninety-eight patients had AF recurrence after a mean follow-up of 17.0 +/- 9.4 months. Those experiencing recurrence had a longer QTc interval than those without recurrence (429 +/- 26 vs. 419 +/- 23 ms, P = 0.004). Multivariate Cox regression analysis demonstrated the QTc interval and left atrial diameter (LAD) as independent predictors of AF recurrence. Patients with a long QTc interval were at an increased risk of AF recurrence (hazard ratio 2.757, 95% CI 1.661-4.611, P < 0.001) after adjustment for multiple factors. The QTc interval had an incremental value combined with the LAD in predicting AF recurrence after RFCA. The patients with a large LAD and a long QTc interval had a much higher AF recurrence rate compared with those with a small LAD and a non-long QTc interval (78 vs. 27%, P < 0.001). QTc interval prolongation is an independent risk factor for AF recurrence after RFCA in hypertensive patients. It provides a simple predictor for identifying the patients with hypertension likely to have AF recurrence after RFCA.