Thoracoscopic surgical ablation has evolved into a valid and effective treatment option, especially in patients with more persistent forms of atrial fibrillation. A significant part of this development is due to the capability of biparietal bipolar radiofrequency clamps to create long-lasting transmural lesions. To date, all commercially available bipolar clamps require a bilateral thoracoscopic approach. Here, we describe the surgical technique of a unilateral left-sided thoracoscopic approach for surgical atrial fibrillation ablation on the beating heart.Copyright © 2020 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.