Nine patients with Fanconi anaemia (FA) were conditioned for HLA-identical sibling bone marrow transplant (BMT) with reduced dose of cyclophosphamide (Cy) without radiation or antithymocyte globulin (ATG). The total dose of Cy was 140 mg/kg (n = 2) or 120 mg/kg (n = 7). The median patient age was 8 years (range 4-19). Graft-versus-host disease (GVHD) prophylaxis was with methotrexate and cyclosporine (n = 8) or cyclosporine alone (n = 1). All patients had sustained engraftment and two developed grade>/= II acute GVHD. Cy toxicity included grade >/= 2 mucositis seen in all evaluable patients and haemorrhagic cystitis in two patients. The Kaplan-Meler survival estimate is 89% with a median follow-up of 285 d (range 56-528). For the purpose of comparison, this report also reviews and updates long-term follow-up data on 32 previously reported FA patients conditioned with 140-200 mg Cy/kg without radiation. The lowest dose of Cy (without radiation or ATG) after which HLA-identical sibling marrow transplant can be successfully performed in FA patients has yet to be determined, but it appears that uniform and sustained engraftment can be achieved with a Cy dose of as low as 120 mg/kg.