Hypertrophic pulmonary osteoarthropathy( HPO) is a rare paraneoplastic manifestation of lung cancer that causes joint pain, joint swelling, and limited range of motion. Two surgical cases of lung cancer with HPO are presented. Case1:A 43-year-old female was referred to our department with a diagnosis of cStage ⅡB left hilar lung cancer. She had difficulty in walking due to arthralgia caused by HPO. Left pneumonectomy was performed and the arthralgia disappeared on the first postoperative day. The patient is being well after surgery without relapse of joint symptoms. Case2:The patient was a 65-year-old male with cStage ⅡA right lung cancer. The symptoms of HPO appeared after he was found to have lung cancer. After right upper lobectomy, the arthralgia disappeared on the first postoperative day. Currently, he is receiving adjuvant chemotherapy, without relapse of joint symptoms.