Many surgeons have investigated local pain associated with posterior spine surgery for cervical or lumbar lesions. However, little information is available concerning local pain after posterior thoracic spine surgery. This prospective study was, thus, performed to investigate the frequency and clinical features of local pain after posterior spine surgery for thoracic lesions. In 29 consecutive patients undergoing posterior spine surgery for various thoracic spinal disorders, local pain was investigated before and after surgery. In all 19 patients with preoperative back pain presumably due to thoracic lesions, pain was well alleviated after surgery. In contrast, 6 patients (21%) newly developed persistent shoulder angle pain after surgery, which resembled axial pain after cervical laminoplasty. In 5 of these 6 patients surgical exposure was extended to the cervicothoracic junction, whereas persistent shoulder angle pain was independent of disease etiologies and surgical procedure, and all of the 5 patients had no other etiologies of local pain such as surgical site infections, hardware failures, pseudoarthrosis, other metastasis, and vertebral fractures. These results suggest that dissection of muscle attachments to the cervicothoracic junction would play some part in the development of persistent local pain after posterior spine surgery for thoracic lesions, although surgical exposure of the zygapophysial joints at the cervicothoracic junction might be a possible source of postoperative shoulder pain. Therefore, to minimize such surgical complications, muscle insertions into the cervicothoracic junction should be preserved as far as possible.