Invasive sinonasal fungal disease is a potentially fatal complication of chemotherapy-induced immunosuppression and neutropenia. We reviewed the outcomes of seven cancer patients who had been diagnosed with invasive fungal sinusitis; six patients had hematologic malignancies and one had breast cancer. At the time of their sinus diagnosis, all patients had been hospitalized and were receiving combination chemotherapy for their underlying malignancy. Impairment of their immune function was characterized by an absolute neutrophil count of less than 1,000/mm3. Aggressive management of their sinonasal fungal disease consisted of surgical debridement and systemic amphotericin B for all patients, and treatment with granulocyte colony-stimulating factor for two patients. Invasive Aspergillus infection was identified in six patients and invasive Candida albicans infection in one. Although the prognosis for these patients was poor and two patients died of the fungal infection, the aggressive treatment strategy resulted in long-term survival for the remaining five patients.