Pneumothorax is a rare surgical complication in spinal surgery with thoracic pedicle screws. The penetrating endplate screw (PES) technique has been developed as a strong alternative spinal anchor to conventional pedicle screws for diffuse idiopathic skeletal hyperostosis (DISH). We present an intraoperative pneumothorax without deviation to the thoracic during the maneuver of the PES. A 56-year-old male who presented with non-union of DISH-related T12 vertebral fracture underwent T12 kyphoplasty and T10-L2 posterior fixation using the PES technique. The left pneumothorax was developed postoperatively without screw deviation to the thorax throughout screw insertion. Postoperative CT suggested that a displaced rib head by the lateral misposition of the screw at the inserting point and the pedicle level might injure the pleura. Spine surgeons should know that the lateral insertion of PES has a potential risk for pneumothorax by the displacement of the rib head because of screw trajectory from caudal to cranial apart from conventional pedicle screw.