To avoid the scar caused by the conventional transcervical thyroidectomy, various techniques of endoscopic thyroidectomy (ET) were developed for excellent postoperative cosmesis.1 However, ET needs to create enough working space via a dissection flap because there is no natural orifice access to the thyroid. Hence, we tried to find a balance between cosmesis, trauma, and en bloc tumor resection, which means simultaneous thyroid tumor removal and central neck dissection. Retroauricular single-site endoscopic thyroidectomy (RASSET) achieves superior cosmetic outcomes by concealing the incision in the single auricula posterior sulci. To minimize surgical trauma, the working space is created in the superficial layer of deep cervical fascia (DCF) between the sternocleidomastoid muscle (SCM) and platysma muscle, with a flap dissection area just between the strap muscles (sternohyoid, sternothyroid, omohyoid, and thyrohyoid) and the anterior border of the SCM. The thyroid gland, the recurrent laryngeal nerve (RLN), and the common carotid artery, surrounded by the middle layer of DCF, are fully exposed by pulling apart the strap muscles and SCM, which enables en bloc tumor resection in this layer (Figure, B). These operations make full use of the characteristics of natural anatomical structures and meet the requirements of membrane anatomy.