Visceral fungal infections are difficult to manage in patients with collagen diseases and immunocompromised hosts. In particular aspergillosis can be a life-threatening complication in these patients. Here we report that combined use of two antifungal agents (micafangin and itraconazole) was effective against severe aspergillosis of the bilateral pleural cavities in a 48-year old male patient diagnosed with Wegener's granulomatosis. Immunosuppressive therapy with corticosteroids and cyclophosphamides improved his nasal and pulmonary symptoms, but inflammation of the bilateral pleural cavities caused bronchial fistulas. Aspergillus fumigatus then infected the bilateral pulmonary cavities through these fistulas. This patient was treated with combined therapy of ITCZ and MCFG was given to this patient because of the risk of renal dysfunction associated with AMPH-B. After 5 weeks of treatment his clinical findings had improved and the fungus was suppressed.