Abstract Objective The purpose of this study was to evaluate the impact of adhering to a strict follow up regimen on mid-term efficacy of intraoperative radiofrequency ablation in maintaining sinus rhythm for patients with atrial fibrillation undergoing cardiac surgery. Methods We enrolled 52 patients with atrial fibrillation and valve disease divided in 2 groups: group 1 (26 patients) underwent intraoperative radiofrequency ablation and was followed by a team of skilled cardiologists who treated recurrences with amiodarone and electrical cardioversion; group 2 (26 patients) was treated with intraoperative radiofrequency ablation but patients were thereafter treated by their local hospital or personal cardiologist. Results There were no intraoperative deaths or complications related to radiofrequency ablation. Twenty four months after the operation, freedom from atrial fibrillation was 60% in group 1 and 32% in group 2 ( p = 0.02). Group 1 also showed a reduction in atrial volume ( p ≤ 0.05). Conclusion Postoperative follow up with electrical and pharmacologic cardioversion combined with radiofrequency ablation achieves higher rate of sinus rhythm maintenance. After ablation, electrical cardioversion is effective even in patients with enlarged left atrium, long history of atrial fibrillation, or previous failed electrical cardioversion.