Invasive aspergillosis of the nasal cavity and paranasal sinuses is characterized by invasion and destruction of the bony sinus walls, the orbit, and other soft tissues of the face. It occurs particularly in patients with severe immune deficits, and less frequently in patients with diabetes mellitus. The therapeutic outcome of invasive aspergillosis is unsatisfactory. Mortality rates range from 50 to 80%, depending primarily on the underlying disease. In general, the prognosis depends on making a prompt diagnosis of infection and providing early treatment. However the diagnosis of invasive aspergillosis is difficult because there is no specific symptom, nor any rapid diagnostic method for confirmation. We report a case of a 64-year old woman with diabetes mellitus and invasive aspergillosis of the nasal septum. She was diagnosed by biopsy of the nasal septum and treated with systemic antifungal agent and surgical debridement. (Ed- paragraphs combined here) In conjunction with this case we review the previous literatures and suggest that prompt antifungal therapy with glycemic control is an important element in the treatment of invasive aspergillosis in a diabetic patient.