A 73-year-old man was admitted to our hospital with pancytopenia in December, 1992. The data of his peripheral blood were as follows: WBC 1,100/microliters (stab 9.0, seg 11.5, eosin 3.5, mono 1.0, lymph 75.0), RBC 176 x 10(4)/microliters, Hb 6.6 g/dl, platelet 4.6 x 10(4)/microliters. Bone Marrow was hypocellular (cell count 1.4 x 10(4)/microliters) and consisted of 30% blasts (peroxidase positive). He was diagnosed as having hypoplastic leukemia. Oral administration of cytarabine ocfosfate (50 mg/day) was begun from the 5th of January, 1993. The dose of cytarabine ocfosfate was increased to 100 mg/day since the 13th of January, 1993, and he was discharged from the hospital on the 23rd of January, 1993. Since then, he has been treated with cytarabine ocfosfate alone in the outpatient clinic. Pancytopenia began to improve in one month, and the data on the 7th of May, 1993 were as follows: WBC 3,500/microliters (stab 2.0, seg 37.5, eosin 1.5, baso 1.0, mono 16.5, lymph 41.5), RBC 249 x 10(4)/microliters, Hb 10.4 g/dl, platelet 15.4 x 10(4)/microliters. Bone marrow became normocellular (cell count 22.0 x 10(4)/microliters) and blasts decreased to 3.0%, and complete remission was confirmed. There were no adverse effects.