The authors report two cases of retractile pleuroparenchymatous disease of the upper lobes of non known aetiology. They compare their results with those reported earlier by Stradling (20), Scadding (18), Davies (10) and attempt to identify the specific characteristics of the disease: progressive weight, loss frequent haemoptysis, apical onset, most often unilateral, with pleural involvement and progressive spread of the lesions which nevertheless remain predominantly in the upper lobes and are asymmetrical. The similarity with pulmonary fibrosis which occurs in ankylosing spondylitis is remarkable.