Aspergillus vegetative endocarditis developing in a patient with acute lymphocytic leukemia during the phase of hematological remission has led to a fatal outcome, complicated with severe hemolytic anemia with red cell fragmentation. Systemic aspergillosis may involve heart valves with underlying disorders, but seldom affects intact valves even in severely compromised hosts. Among such rare cases so far reported, only 2 cases have been documented in acute leukemia, despite a huge prevalence of pulmonary and systemic aspergillosis in hematological malignancies. Our present case is essentially the same as in the preceding two cases in that endocarditis occurred during the hematological remission. These clinical observations may suggest that every leukemic patient suffering from aspergillosis is susceptible to the valvular complication after, rather than during, the period of severe myelosuppression, because platelets play an important role in the formation of thrombotic lesions.