The mucormycosis is a group of serious opportunistic infections caused by fungi of the class Zygomycetes and order Mucorales. Pulmonary mucormycosis is a relatively rare disease but typically manifested by a rapidly progressive, often fatal pneumonia in patients with diabetes mellitus, hematologic malignant neoplasms, or organ transplants. The radiologic manifestations of pulmonary mucormycosis are nonspecific and include progressive lobar or multilobar consolidations, pulmonary masses and pulmonary nodules. Recently, we experienced a pulmonary mucormycosis in 32-year-old man with uncontrolled diabetes. He complained of cough, left pleuritic chest pain and generalized weakness. Initial chest X-ray finding was the consolidation on the lower lobe of the left lung. On the sixth hospital day, bronchoscopic examination with lung biopsy revealed broad, non-septate hyphae with right-angle branching, diagnostic of mucormycosis, and consequently amphotericin B therapy was started. We performed a lobectomy of the left lower lobe of the lung on 29th hospital day.