We report first case of pulmonary siderosis appearing as a consolidation upon radiological examination and being misdiagnosed as pneumonia. A 59-year-old man visited our hospital with a cough and sputum that had persisted for more than a month. He had undergone chest computed tomography (CT) after abnormal findings on chest X-ray at other hospitals. Based on the chest CT results, he was diagnosed with pneumonia. He was then administered antibiotics for 3 weeks, but there was no improvement. We identified the patient's occupational history first, and then performed bronchoalveolar lavage and chest CT-guided transthoracic lung biopsy. The obtained specimen showed alveolar, macrophage-containing, Prussian blue-positive iron particles. Based on the results, we diagnose/d the patient with pulmonary siderosis. We advised him to discontinue his job. He is currently undergoing observation, and has not shown any special symptoms.