Rounded atelectasis of the lung was first described by Loeschke in 1928 in association with pleural effusion. 1 : Rounded atelectasis is an atelectasis of a peripheral part of the lung due to pleural adhesions and fibrosis causing deformation of the lung and bending of some small bronchi. The pleural surfaces then fuse to one another, trapping the underlying lung and leading to atelectasis. As a result of this alteration, a mass lesion that mimics lung cancer can be seen on the PA chest radiograph. This lesion is most easily appreciated to be a pseudotumour with use of CT scanning. HRCT can non-invasively demonstrate continuity to areas of diffuse pleural thickening, evidence of volume loss in the adjacent lung or a characteristic comet tail of vessels and bronchi sweeping into a wedge-shaped mass. Other names for this condition are Blesovsky's syndrome, Helical atelectasis, Folded lung, Pleuroma, Atelectatic pseudotumour, Shrinking pleuritis and Pulmonary pseudotumour. It has a yearly incidence of 5-15 cases/100,000 people. The most common cause of rounded atelectasis is occupational exposure to mineral dusts: asbestosis, pneumoconiosis, inhalation of mixe d mineral dusts. 2 ; however, any cause of pleural inflammation can cause round atelectasis. Rounded atelectasis is less common in pulmonary diseases directly affecting pleura such as in legionellosis, histoplasmosis and in patients with end-stage renal disease. Atelectasis may also occur in the course of sarcoidosis and in young adults without history of pulmonary disease. 3 In our case, it was tubercular in origin.