Atrial fibrillation (AF) is the most common arrhythmia, and renin-angiotensin system blockade (RAS-B) may be favorable for AF because of its effect on cardiac remodeling. However, effects of RAS-B on AF in hypertensive patients are controversial. Thus, in this study, we investigated the long-term effects of RAS-B on cardiac remodeling and rhythm control after electrical cardioversion for hypertensive patients with persistent AF. We studied 27 consecutive hypertensive patients with persistent AF (duration > one week) who received electrical cardioversion and once recovered to sinus rhythm. Blood pressure of the patients was controlled by medication including RAS-B. The patients were divided into those who were pre-treated with RAS-B (n = 10) for at least two months before electrical cardioversion and those without RAS-B (n = 17). We performed echocardiography before electrical cardioversion and 3 years after electrical cardioversion in all patients and compared the differences in echocardiographic cardiac remodeling parameters, including left atrial dimension, left ventricular end-diastolic dimension and left ventricular ejection fraction. The AF recurrence-free ratio during the follow-up period was significantly higher in the RAS-B group than in the non-RAS-B group, judged by Kaplan-Meier analysis (60 vs. 24%, P = 0.01). All cardiac remodeling parameters in the RAS-B group showed better values than those in non-RAS-B group (each parameter, P < 0.05), supporting the beneficial effects of RAS-B on AF in hypertensive patients. In hypertensive patients with AF, pre-treatment with RAS-B before electrical cardioversion can prevent cardiac remodeling for 3 years and maintain sinus rhythm.