A case of congenital aplasia of the left lung in a young Korean male is presented together with a review of the literature. The patient was 25 years old man who had suffered form intermittent exertional dyspnea and left chest discomfort for five months. Until that time, he was healthy and he had no specific symptom or sign. The diagnosis was confirmed by chest films, tomography, lung scanning, bronchography and pulmonary arteriography.