Two children affected by severe aplastic anaemia (SAA) underwent allogeneic bone marrow transplantation (BMT) using partially matched family donors. In both cases there was a successful engraftment of donor haemopoietic stem cells. However, after an initial erythropoietic recovery, 5 months following BMT both children became severely anaemic. Although multiple factors were responsible for anaemia, in both cases there was a markedly impaired erythropoietin response to anaemia, as indicated by the inappropriately low levels of serum erythropoietin (EPO). Treatment with recombinant human erythropoietin (rHuEPO) induced a sustained erythropoietic response with complete correction of anaemia. This pilot study suggests that rHuEPO can be effective in correcting long-lasting anaemia after marrow transplantation, characterized by inadequate erythropoietin production.