Swyer-James syndrome was usually diagnosed on the past history and the radiologic features, and almost all the cases were followed by the conservative therapy. Therefore, the examination of the pathologic features was rare. We recently experienced a patient with Swyer-James syndrome, who had a history of respiratory infection from his childhood onward and whose chest radiograph revealed hyperlucency of the right lower lung field. A standard right middle and lower lobectomy was performed. Histological examination of the resected specimens revealed hypoplasia of alveoli and pulmonary artery.