Background: Postoperative bleeding is a rare but serious complication occasionally caused by hard surgical materials, such as staples. Postoperative hemorrhage caused by sutures is very rare.
Case presentation: A 75-year-old man with lung cancer underwent right lower lobectomy. Eleven days after surgery, he developed a haemothorax. Emergency thoracotomy revealed arterial bleeding from a pinhole injury in the parietal pleura caused by a monofilament non-absorbable suture tip used during the initial surgery.
Conclusions: Postoperative bleeding is a serious complication, and as sutures are often used in surgery, it is important to be cautious while using this material.
Keywords: Haemothorax; Lobectomy; Postoperative bleeding.