Pulmonary gangrene is a rare and severe complication of bacterial pneumonia, where a pulmonary segment or lobe is sloughed due to parenchymal devitalization of the parenchyma, with secondary anaerobic infection and necrosis caused by pulmonary vascular thrombosis. Prior to the antibiotic era, massive pulmonary gangrene was potentially fatal. Herein, a case of pulmonary gangrene in a 67-year-old man is reported. He complained of fever, chills, dyspnea and purulent sputum of 5 days duration. The plain chest radiograph showed well-marginated right upper lobe consolidation, with bulging minor fissure, suggestive of a Klebsiella infection. A contrast CT scan demonstrated consolidation of the right upper lobe, with a central necrotizing portion. Klebsiella species was confirmed from both sputum and blood cultures. After appropriate antibiotics, the chest X-ray and CT scan 3 weeks later showed a large cavity with an air-fluid level, sloughing-off and extrusion of necrotic lung tissue, suggestive of pulmonary gangrene. Seven months later, the right gangrenous lung showed severe volume loss on a chest radiograph. The management of pulmonary gangrene has been somewhat controversial. Herein, it was managed without surgical drainage or resection. If the antibiotic therapy had failed, then a surgical approach would have been considered.