One case of aspergillosis and mucormycosis occurring in a patient with stage-IV Castleman disease was investigated. The patient, who had undergone polychemotherapy and was in otherwise good general condition, without lymphadenopathies or imbalance of the immune system, presented with a palatal ulceration that progressively involved the palatal mucosa and bone, the paranasal sinuses and the orbit. Repeated cultural examinations were always negative. He had undergone multiple cytological smears of the inflammatory infiltration and biopsies of both the oral and nasal mucosa, which resulted in extensive necrotic debris and suppurative inflammation, and, on the very last biopsy, fungal hyphae, spores and conidia were also detected. These were large, branching, mostly non-septate hyphae, associated with conidiophores and conidia, the latter appearing dark brown to black in the histological preparations. Following the diagnosis of combined mucormycosis and aspergillosis, the patient underwent prolonged topic and systemic antibiotic treatment that resulted curative. Mucormycosis usually is a fatal complication of head and neck or systemic disorders, leading to severe immune suppression. Nevertheless, early diagnosis may be achieved using a combination of special stains and may lead to effective antibiotic treatment and cure of the patient, even if associated with other opportunistic infections, such as aspergillosis.