To study the changes of visceral mycoses in autopsy cases, data on visceral mycosis cases with leukemia and myelodysplastic syndrome (MDS) reported in the Annual of the Pathological Autopsy Cases in Japan in 1989, 1993, 1997 and 2001 were analyzed. The frequency rate of visceral mycoses with leukemia and MDS was 27.9% (435/1,557) in 1989, 23.0% (319/1,388) in 1993, 22.3% (246/1,105) in 1997 and 25.1% (260/ 1,037) in 2001, which was clearly higher than the rate of cases without leukemia and MDS: 3.4%, 2.7%, 3.5% and 3.7%, respectively. Furthermore, in comparing the rate of mycoses in recipients of stem cell transplantation with that of non-recipients, that of recipients was about 10% higher. The predominant causative agents were Candida and Aspergillus, at approximately the same rate (Candida 33.6%, Aspergillus 33.3%) as in 1989. However, Aspergillus increased conspicuously in 1993 (Candida 22.3% Aspergillus 44.5%), and continued to increase (Candida 22.8%, Aspergillus 50.8% in 1997; Candida 16.9%, Aspergillus 54.2% in 2001). In aspergillosis and zygomycosis, the lung and bronchi comprised the most commonly infected organs: 74.7% and 75.6% of the total cases, respectively. Among a total of 1,260 cases with mycotic infections in the four years studied, acute lymphatic leukemia and acute myeloid leukemia were the major diseases (35.5% and 33.5%, respectively) followed by MDS (29.0%). Given these facts, we emphasize that a greater interest in mycoses should be taken by clinicians, and immunocompromised patients should be protected from opportunistic invasive fungal infections, especially aspergillosis.