Pulmonary venous isolation has emerged as an effective therapy for atrial fibrillation (AF); however, AF recurrence is common. The aim of the present study was to investigate the effect of angiotensin receptor blockers (ARBs) on the recurrence rate of AF following ablation therapy. In total, 120 patients, who were scheduled for ablation, were randomly selected. The patients were randomly divided into three groups, which received treatment with a placebo (n=40), 80 mg valsartan daily (n=40) or with 160 mg valsartan daily (n=40). The demographic characteristics, comorbidities, AF type and information regarding treatment with ARBs were recorded and analyzed. Following a mean follow-up period of 13.8 +/- 8.6 months, 66.7% of patients were found to be free of AF. Kaplan-Meier analysis of the time until the first recurrence during the follow-up period revealed that patients treated with 160 mg/day valsartan presented a higher probability of remaining free of AF (88%, vs. 47% for the control and 65% for the 80 mg/day valsartan groups). In addition, multivariate analysis demonstrated that treatment with ARB was associated with lower AF recurrence rates (hazard ratio, 0.46; 95% confidence interval, 0.20-0.93] P=0.01). In conclusion, treatment with 160 mg/day valsartan markedly reduced the risk of recurrence of AF in a dose-dependent manner in AF patients following ablation.