Surgery is a cornerstone of treatment in early-stage non-small cell lung cancer. Chronic postoperative thoracotomy pain, post-thoracotomy pain syndrome (PTPS), is a condition occurring in 50% of postsurgical patients with lung cancer and is largely unrecognized. This article examines the diagnosis and treatment of PTPS to assist oncology nurses in providing better care to this patient population. Post-thoracotomy pain in patients with lung cancer may be under-reported and undertreated. Causes from the thoracotomy can be trauma and compression to the intercoastal nerves, fractured and compressed ribs, inflammation of the chest muscles, atrophy of chest muscles, or scar tissue rubbing. This article examines the diagnosis and treatment of PTPS to assist oncology nurses in providing better care to this patient population. If left untreated, chronic pain can have a deleterious effect on patients' recovery and overall well-being. Oncology nurses should be aware of the signs and symptoms of PTPS so that more patients are diagnosed and choose to seek treatment.