Unilateral pulmonary aplasia (agenesis) is a rare congenital anomaly. Associated anomalies are found in more than 50% of the patients, mainly involving the cardiovascular, gastro-intestinal, musculoskeletal, urogenital systems. It is usually diagnosed in childhood but patients who have no or mild associated anomalies may survive into adulthood. We present a case of pulmonary aplasia since it is a rare clinical entity.