Congenital cystic disease of the lung is very rare and controversial disease. But in general is regarded as developmental anomaly. Occasionally failure of the primitive lung bud to develop combined with cardiac anomaly had been reported but it was very rare. Recently a case of cystic lung disease combined with pulmonic valvular stenosis was seen in this clinic with clinical pictures of nonspecific respiratory infection and X-ray finding very similar to that of far advanced pulmonary tuberculosis, destroyed left lung. This case was treated by closed pulmonic valvulotomy and left side pneumonectomy successfully.[KTCS 1977;1:118-123]