Congenital malformations of the lung, which may vary in degrees of severity, are very rare diseases. Pulmonary artery agenesis is a rare anomaly that may occur during the early involution of the proximal portions of the sixth aortic arch, during embryological development of the heart. This agenesis may be accompained by a complete or partial absence of the lung and its bronchus on the same side, which is diagnosed as pulmonary agenesis. In the great majority of the cases, the diagnosis is usually made at or soon after birth and it can be associated with multiple anomalies. However, extremely rare asymptomatic cases may go unnoticed until adulthood. We are presenting a patient with unilateral right pulmonary agenesis, who survived through adulthood without any symptoms and other congenital anomalies. The multislice computed tomography findings and differential diagnoses have been discussed.