Although a septal-superior approach provides excellent exposure of the mitral valve, it requires novel strategies for concomitant ablation in patients with atrial fibrillation. Utilizing a combination of bipolar radiofrequency and cryothermy, we developed a novel technique for creating a biatrial lesion set via a septal-superior approach during mitral valve surgery. We treated 10 patients with functional mitral regurgitation and permanent atrial fibrillation with rhythm disturbance for a mean 87 months. A modified maze was successfully accomplished via a septal-superior approach in all. The mean follow-up period was 18 months, during which permanent pacemaker implantation was necessary for one due to sinus bradycardia. Sustained sinus rhythm, including atrial or atrial-based paced rhythm, was present in all immediately after surgery, in 70% at discharge, in 80% at 1 year after surgery, and in 90% at the latest follow-up examination. Our novel technique using a modified maze procedure in combination with mitral valve surgery via a septal-superior approach was safe and useful for eliminating atrial fibrillation, with a relatively low frequency of sinus node dysfunction.