Thoracic disc herniation is a rare condition in which a posterior approach, extrapleural approach, posterolateral approach, or transthoracic approach is currently used. The posterior approach is not recommended in thoracic disc herniation surgery because of the risk of spinal cord injury. The transthoracic approach makes it possible to remove the intervertebral disc and is considered a standard method. However, due to an extensive transverse skin incision, division of the latissimus dorsi muscles, and rib resection, the conventional open approaches involve a risk of complications, such as infection and post-thoracotomy pain syndrome; and a long period of rehabilitation and recovery is required. Excision of the intervertebral disc under thoracoscopic guid-ance can reduce the damage to the skin and muscles, but the equipment and surgical materials are expensive and a long learning curve is required. Therefore, we report a case and a new muscle splitting transthoracic approach that can be performed by incising 10 cm of skin longitudinally and preserving the serratus anterior and latissimus dorsi muscles.