We describe two cases of disseminated mucormycosis following allogeneic bone marrow transplantation (BMT). Both patients were suffering from chronic graft-ver-sus-host disease (GVHD) and treated with prolonged administration of corticosteroid. In both cases, the initial symptoms were high fever and left flank pain. Involved organs were the spleen, right kidney and the right lung in one case, and the spleen and the brain in the other. The diagnosis was confirmed by pathology after splenectomy. One patient, in whom the immunosuppressesants could be discontinued, was treated with prolonged conventional and liposomal amphotericin B and 5-fluorocytosine. The other, in whom the immunosuppressants could not be discontinued due to extensive GVHD, was unresponsive to amphotericin B, and eventually died from the fungal infection. Although mucormycosis, especially the disseminated form thereof is infrequent, it should be considered in high-risk patients because early diagnosis and timely therapy combining antifungal drug or surgery and reduction of immunosuppression appear to improve the prognosis.