We report a case of postpneumonectomy syndrome in a 75-year-old man operated on for right lung cancer 18 months previously. The patient had a pre-existing severe thoracic scoliosis. Treatment involved positioning of an expandable silastic prosthesis in the postpneumonectomy cavity. A favorable outcome was observed. We think that a pre-existing scoliosis could be considered as a potentially predisposing factor to the development of the syndrome.