Neutropenia is a rare complication of Diamond-Blackfan syndrome (congenital hypoplastic anaemia). Three patients are reported: all had neutropenia as well as anaemia, and to investigate the cause of the neutropenia culture of bone marrow for granulocyte-macrophage colony forming cells (GMCFCs) was performed. Two cases had a low incidence of GMCFCs, but the third case had a high incidence. These findings suggest that myeloid precursors can be abnormal in Diamond-Blackfan syndrome and that the mechanism of neutropenia may, like that of anaemia, vary from patient to patient.