Lung herniation is a rare condition which has only been mainly published as case reports in the literature. Although its description has been around since 1845, not much is still known about it. More often seen after trauma or as a surgical complication post thoracic surgery, it's management usually depends on its etiology and varies between individuals. We report a case of lung herniation after positive pressure ventilation from a previous thoracotomy site. To our knowledge, this is the first report where the lung herniation was precipitated by mechanical ventilation.