Patients with previous invasive fungal infections (IFI) are at high risk of reactivation of the infection during BMT, even after an apparently curative antifungal treatment. We report four patients who suffered an IFI after intensive chemotherapy for acute leukemia and were later submitted for BMT. One patient had developed a chronic systemic candidiasis during consolidation chemotherapy and received prophylactic oral or iv fluconazole (200 mg daily) throughout BMT. Two patients developed an invasive pulmonary aspergillosis after intensive chemotherapy, one of them after salvage therapy for post-allogeneic BMT relapse and the other after consolidation therapy. The former patient underwent partial lobectomy after treatment with amphotericin B before a second allogeneic BMT was performed. Both patients received prophylactic itraconazole (400 mg daily by mouth) throughout the BMT procedure. The fourth patient had pneumonia caused by Scedosporium apiospermum (the anamorph form of the fungus Pseudallescheria boydii) during consolidation chemotherapy which was successfully treated with itraconazole. During BMT he also received oral itraconazole (400 mg daily) as prophylaxis against reactivation of the infection. All four patients had successful BMT and none had clinical, radiological or microbiological evidence of reactivation of IFI during BMT.