Swyer-James/MacLeod Syndrome is a rare disease which is characterized by unilateal hyperlucent lung due to hypoplasia of its pulmonary artery. A non-smoker, 57 years old female patient admitted to our clinic with cough, sputum production and fever. Her medical history revealed that these symptoms has been recurrent since her childhood. Furthermore she had been followed up with as a patient of chronic bronchitis or bronchiectasis outside of our clinic so far. Physical examination revealed diminished respiratory sounds and coarse crackles onmiddle and lower zones of left hemithorax. Chest X Ray showed hyperluceny and volume loss of the left lung and bronchiectasis at the left lower zone. Computerized and High Resolution Computerized Tomography revelaed hypoplasia of left pulmonary artery with reduced diameters of its branches, hyperlucent left lung and cyctic bronchiectasis in left lower, and superior and lingular segments of the left upper lobes. Colored Doppler Echocardiography showed hypoplasia of the left pulmonary artery and enlargement of the main pulmonary artery. Swyer-James/MacLeod Syndrome is diagnosed in childhood or early adulthood of most of the cases. We present this case to emphasize the delayed diagnosis until the age of 57 although she had been investigated several times because of her recurrent symptoms since her childhood and to emphasize considering this syndrome especially when a hyperlucent lung was detected on chest X ray.