It has been proposed that intensive chemotherapy ror RAEB is dangerous, and a small dose of ara-C therapy is recommended in many institutes for its ability to differentiate leukemic cells. Combination chemotherapy for RAEB, however, has not been completely evaluated. We introduced B-DOMP therapy, which is used in our hospital, for RAEB. B-DOMP therapy includes Behenoyl ara-C, daunomycin, oncovin, 6-MP and prednisolone, which achieved approximately 80% of complete remission of ANLL for adults. Five males and one female of RAEB, aged 40-74 (median 70), were treated by B-DOMP regimen. Two cases achieved complete remission, 2 remained in partial remission and 2 cases died within one month. In three cases, the cause of death was fungal pneumonia. It must be stressed that life-threatening pneumonia was common after chemo therapy for RAEB, and careful protection against fungal infection using laminarair flow is required.