This retrospective survey of the EBMT Leukaemia Working Parking describes 78 patients with myelodysplasia (MDS) or secondary acute myelogenous leukaemia (sAML) who were given an allogeneic bone marrow transplant (BMT). The status of underlying disease at the time of transplantation was prognostic for the two-year disease-free survival which was 60% for patients transplanted in complete remission. Similar results were obtained for those with less advanced MDS (50-64%) who had not received any prior intensive chemotherapy. The results were significantly less favourable for those with more advanced disease who only partially responded to prior intensive chemotherapy (18%) while none of those who either relapsed or were resistant to chemotherapy survived. Allogeneic BMT can therefore be considered as curative treatment for patients with MDS. Patients with sAML who have a histocompatible donor should be given chemotherapy intensive enough to induce complete remission. If this is achieved these individuals have a prognosis comparable to those with de novo AML in first remission after BMT.