The patient most susceptible to invasive aspergillosis has had prolonged granulocytopenia resulting from intensive chemotherapy and/or radiation therapy, aplastic anemia, or acute leukemia. The sinuses and lungs are usually involved, but the infection may disseminate to the endocardium, skin, CNS, and eye. Efficacy of antifungal treatment with amphotericin B depends on early recognition and aggressive intervention. In severe or refractory cases, addition of flucytosine, rifampin, or fluconazole may be beneficial. The most ominous presentation of zygomycosis involves sinus and orbital destruction and necrosis. However, pulmonary involvement is the most common manifestation in cancer patients. Infections with Pseudallescheria boydii, Fusarium species, and Trichosporon beigelii are increasingly being recognized in cancer patients, as are Malassezia furfur and invasive mycoses from dematiaceous molds.