Surgical isolation of left atrial posterior wall (box lesion) with left atrial appendage closure are good options for treating patients with atrial fibrillation concomitant with another cardiac surgical procedure in case we prefer not to open the left atrium. We describe a full box ablation, left atrial appendage closure and aortic valve replacement through a J-shaped ministernotomy through the fourth intercostal space. The box lesion ablation is performed using the Isolator Synergy and Bipolar RF Ablation Clamp with the jaws placed in the oblique and transverse sinuses from the right side. The left appendage is excluded and electrically isolated with the AtriClip Flex-V; the aortic valve is replaced by a sutureless Perceval bioprosthesis. This technique allows us to perform a complete box lesion and left atrial appendage  closure easily for patients with paroxysmal or persistent atrial fibrillation in which we do not open the left atrium, such as those with aortic valve surgery and/or coronary artery bypass grafting.