A 38 year-old woman admitted for bilateral infiltrates with a cavity and treated diabetic ketoacidosis and elevated inflammatory reaction in clinical examination was found in transbronchial lung biopsy specimens to have bilateral pulmonary mucormycosis. We controlled blood glucose with insulin and removed bilateral pulmonary lesions separately. Pulmonary mucormycosis with diabetic ketoacidosis is a rare but fatal fungal infection. Early diagnosis, intensive insulin therapy, and surgical resection may save patients with pulmonary mucormycosis even if lesions are bilateral.