Sino-orbital invasive aspergillosis has been regarded as a lethal disease. The authors report a case with a successful treatment result. A 65 year-old woman, with mild diabetes mellitus, presented progressive right visual disturbance, diplopia, ptosis, and severe periorbital pain over a period of 2 weeks. MR images with gadolinium contrast showed a heterogeneously enhanced mass extending from the right orbital apex to the cavernous sinus. Despite steroid pulse therapy, her symptoms progressed. An open biopsy revealed invasive sino-orbital aspergillosis. Intravenous and oral antifungal agents were administered, but the aspergilloma gradually expanded. Her general status deteriorated due to intractable periorbital pain that was resistant to narcotic analgesics. By a craniotomy, the aspergilloma involving the orbit and cavernous sinus was radically removed leaving the internal carotid artery intact and simultaneously rhizotomy of the trigeminal nerve was carried out. The postoperative course was uneventful and the pain was remarkably ameliorated. Three years after the surgery, she has been well, receiving voriconazole and experiencing no relapse of the disease.