Twenty-five elderly patients with oligoblastic acute myeloid leukemia (AML) received subcutaneous granulocyte colony-stimulating factor (filgrastim) in addition to supportive care. Ninety-two percent of the patients had multilineage dysplasia, 17% hypoplasia, and 48% a high-risk karyotype. During filgrastim treatment neutrophil and platelet counts increased significantly (p<0.0001 and (p=0.042), respectively) and 3/13 patients (23%) no longer required transfusions. A complete peripheral hematologic response (CHR) was obtained in eight (32%) and marrow blast cell clearance (<5%) in five patients (20%), lasting 12 and 10 months, respectively. Filgrastim caused osteomyalgia and fever in 20% of cases. The median survival was 8 months overall, and 15 months in patients who achieved a CHR. Filgrastim may be a useful adjunct to supportive care in elderly patients with poor-risk AML.