We report a rare case of invasive pulmonary aspergillosis invading the mediastinum and the left atrium. A 38-year-old female was hospitalized for cough, shortness of breath and fever. She had a past medical history of tuberculosis. Computed tomography (CT) scans identified an ill-defined enhancing mediastinal soft tissue density mass encasing the heart and major vessels. The cardiac echocardiography showed global hypokinesia, low ejection fraction and a large echogenic density in the left atrium. The pathology from the bronchoscopic biopsy observed abundant fungal hyphae which were stained with periodic Acid-Schiff and Gomori's methenamine silver. Despite the treatment with antifungal agents, the patient could not be saved. Invasive pulmonary aspergillosis, which involves the mediastinum and the heart, is very rare in immunocompetent patients.