Objective The Cox maze Ⅲprocedure has excellent long-term efficacy in curing atrial fibrillation. It has not been widely practiced because it is technically challenging and requires prolonged cardiopulmonary bypass. The aim of this study was to examine a simplified Cox maze Ⅲprocedure that uses bipolar radiofrequency energy as an ablative source. Methods Beginning January 2002, a total of 40 consecutive patients underwent a modified Cox maze Ⅲprocedurewith bipolar radiofrequency energy. Nineteen had a lone maze procedure and 21 had a maze procedure plus a concomitant operation. Onemonth after the operation, the first 8 patients were investigated with highresolutionmagnetic resonance imaging. Patientswere followed up monthly with clinical examination and electrocardiography. Results There was no operative deaths. The crossclamp times were 47±26 minutes for the modified lone Cox maze Ⅲprocedure and 92±37 minutes for the Coxmaze Ⅲprocedure plus concomitant procedures. These were significantly shorter than our previous times for the traditional Cox maze Ⅲprocedure(93±34 minutes and 122±37 minutes, respectively, P < .05). Follow-up magnetic resonance imaging showed no evidence of pulmonary vein stenosis, and atrial contractility was preserved in all patients. There were no late strokes. At 6-month followup, 91%of patients (21/23) were in sinus rhythm. Conclusions Bipolar radiofrequency ablation can be used to replace the surgical incisions of the Cox maze procedure. This energy source did not result in pulmonary vein stenosis. The modification of the Cox maze Ⅲprocedure to use bipolar radiofrequency ablation simplified and shortened this procedurewithout sacrificing short-term efficacy. Objective The Cox maze Ⅲprocedure has excellent long-term efficacy in curing atrial fibrillation. It has not been been practiced because it is technically challenging and requires prolonged cardiopulmonary bypass. The aim of this study was to examine a simplified Cox maze Ⅲprocedure that uses bipolar radiofrequency Nineteen had a lone maze procedure and 21 had a maze procedure plus a concomitant operation. Onemonth after the operation, the Patients There were with highresolutionmagnetic resonance imaging. Patients There were no operative deaths. The crossclamp times were 47 ± 26 minutes for the modified lone Cox maze Ⅲprocedure and 92 ± 37 minutes for the Coxmaze Ⅲprocedure plus concomitant procedures. These we re significantly shorter than than previous for the traditional Cox maze III procedure (93 ± 34 minutes and 122 ± 37 minutes, respectively, P <.05). Follow-up magnetic resonance imaging showed no evidence of pulmonary vein stenosis, and atrial contractility was At 6-month followup, 91% of patients (21/23) were in sinus rhythm. Conclusions Bipolar radiofrequency ablation can be used to replace the surgical incisions of the Cox maze procedure. This energy source did not result in pulmonary vein stenosis. The modification of the Cox maze Ⅲprocedure to use bipolar radiofrequency ablation simplified and shortened this procedurewithout sacrificing short-term efficacy.