Swyer-James-MacLeod Syndrome (SJMS) or unilateral hyperlucent lung syndrome is characterized by hypoplasia and/or agenesis of the pulmonary arteries resulting in pulmonary parenchyma hypoperfusion. SJMS was first described in 1953 by Swyer and James and considered to be an acquired disease secondary to viral respiratory infections during childhood. We reviewed the clinical and imaging features of SJMS in six adults diagnosed over an 8 year period (2005-2012). The patients9 mean age was 44 years old (27-43 years). One was ex-smoker and the others were non-smokers. The history of childhood respiratory infection was present in 5 patients. The symptoms included shortness of breath in 3, cough in 2, hemoptysis in 2 patients. One of the patients who has no respiratory symptom was referred to our clinic due to weight loss. Additional diseases were asthma for 2 patients, chronic obstructive pulmonary disease and pulmonary hypertension for 1, bronchiectasis for the other 2 patients. All patients were suspected for SJMS due to unilateral loss of lung volume and hyperlucency on chest x-ray. Diagnoses were confirmed by MR angiography for 4, CT angiography for 1, contrasted CT for 1 patient. The left pulmonary artery was defected in 3 and the right pulmonary artery was defected in 3 patients. One patient underwent pulmonary embolectomy because of massive hemoptysis while the others are in a stable course in the follow-up period.