Key Clinical MessagePrimary lung cancer was reported by a bilateral lung transplant patient without any risk factors. Single lung transplantation should be contemplated instead of double lung transplantation as it has been shown to increase the risk of lung cancers.AbstractThis is a case report of a 37‐year‐old woman, with no history of smoking, who developed adenocarcinoma in her transplanted lung 17 years post transplantation. The development of lung cancer 17 years after transplantation is considered as a rare finding in this case report. According to the Annual Report on Cardiothoracic Organ Transplantation 2019–2020, the NHS Blood and Transplant Data, approximately 156 lung transplants were performed in the UK during 2019–2020. The third most common primary disease group recipient was cystic fibrosis and bronchiectasis. There are several medical complications described in the recipients' post‐lung transplantation, and the increased risk of lung malignancy due to immunosuppression is well‐established in comparison to the general population. Most cancers, however, develop in the native lung following a single lung transplant. Several cases of lymphoproliferative malignancies in the transplanted lung have been reported following bilateral lung transplantation. This is a case report of a 37‐year‐old woman with no history of smoking who developed adenocarcinoma in her transplanted lung 17 years later. This patient underwent lobectomy via thoracotomy and was discharged home in good condition. Only a few cases of patients developing primary lung cancer in the transplanted lung with no recipient risk factor have been reported in the literature to date. The development of lung cancer 17 years after transplantation was a rare finding in this case report.