Unilateral absence of pulmonary artery is a rare congenital anomaly that is frequently associated with other cardiovascular abnormalities. Most patients who have no associated cardiac anomalies have only minor or absent symptoms in childhood and survive into adulthood. We experienced a case of unilateral absence of pulmonary artery in a 5 year-old female patient with the chief complaint of abnormal chest X-ray finding. Unilateral absence of pulmonary artery was diagnosed by lung perfusion scan, cardiac catheterization with pulmonary and aortic angiography. So we report this case with brief review of related literatures.