Pulmonary mucormycosis is a rare opportunistic infection caused by Mucormycosis. This fungal infection is uncommon in immunocompetent individuals. Because of its various clinical and imaging manifestations, it is a diagnostic challenge to distinguish pulmonary mucormycosis from other pulmonary diseases, such as carcinoma. Herein, we report a case of pulmonary mucormycosis presenting as Pancoast syndrome and bone destruction of ribs. A 46-year-old Chinese woman was admitted due to pain in chest, right neck and arm for four months and hoarseness for one week. The pre-admission diagnosis via chest CT was pulmonary carcinoma. The subsequent bronchoalveolar lavage fluid analysis and bronchoscopic biopsy were negative for malignant cells, except chronic inflammation. Imaging-guided percutaneous biopsies were carried out after admission and the final pathological diagnosis was pulmonary mucormycosis. Although the patient was started on oral posaconazole of 400mg bid, the disease condition continued to deteriorate. She finally died of respiratory failure.