Phosphatidylglucoside (PtdGlc), a new type of glycolipid, was recently identified. We examined PtdGlc expression in normal blood cells and leukemic cells using an anti-PtdGlc monoclonal antibody, DIM-21. Neutrophils, monocytes, HL-60 cells and a subset of cord blood (CB) CD34⁺ cells, but not erythroblasts, expressed lipid antigen. PtdGlc was preferentially expressed along the neutrophil differentiation pathway of CB CD34⁺ cells treated with cytokines and HL-60 cells treated with retinoic acid. PtdGlc expression was not increased in HL-60 cells treated with phorbol ester. CB CD34⁺ cells contained a population of PtdGlc⁺ cells, and CB CD34⁺PtdGlc⁺ cells produced mainly granulocyte-macrophage colonies and a small number of erythroid colonies. A positive correlation between PtdGlc expression and CD15 expression in leukemic cells from patients with acute myeloblastic leukemia was shown. These results indicate that increasing PtdGlc expression is seen with neutrophil maturation.