A 23-year-old female immigrant from Ethiopia presented with a history of hemoptysis and an abnormal chest x-ray. A computed tomography scan showed that her left lung was greatly shrunken and her right lung was very large but structurally normal. She had a history of multiple respiratory infections as a young child but had been well since the age of five years. Her lung function was within normal limits except for an increased residual volume. It is very likely that her left lung was destroyed early in childhood and that her right lung underwent compensatory growth. She did not show airways obstruction, which is usually seen when compensatory lung growth occurs after surgical removal of lung tissue; this may indicate that, in those cases, the surgery compromised airway function.