(18)F-FDG PET/CT on a 23-year-old woman with aplastic anemia and left periorbital swelling showed FDG-avid lesions in the head and neck. The lesions were confirmed to be mucormycosis histologically after (18)F-FDG PET/CT-guided biopsy. Antifungal therapy was adjusted with serial follow-up (18)F-FDG PET/CT until complete patient recovery. (18)F-FDG PET/CT is valuable in the diagnosis and management of mucormycosis.