A 78-year-old man administered prednisolone and cyclosporin A for bullous pemphigoid and found in computed tomography (CT) to have a left-lung nodule was suspected of having a fungal infection due to elevated blood (1→3)-β-D-glucan. Despite empirical antifungal therapy, however, the nodule grew, followed by new nodules in both lungs. Disseminated nocardiosis was eventually diagnosed based on sputum, blood, and skin cultures growing Nocardia sp. Antinocardial treatment with imipenem/cilastatin and amikacin was started. The patient then developed pneumocystis pneumonia for which pentamidine was added. He had recovered completely when antimicrobial therapy was completed. A wide variety of microorganisms may infect patients with impaired cellular immunity, simultaneously involving multiple organisms in some cases. Definitive microbiological diagnosis with culture or biopsy specimens is therefore crucial for appropriate management.