We report a case of autoimmune haemolysis after an ABO- and ABDR-identical kidney transplantation which leads to the discussion of the role of cyclosporin A (CsA). A 46-year-old woman with end-stage renal disease and no history of auto-immune disease received an ABO- and ABDR-identical first renal allograft from a cadaver donor. On day 16, while on a heavy sequential immunosuppressive regimen including anti-thymoglobulins, azathioprine (Aza), prednisolone (Pred) and CsA, she developed an autoimmune haemolysis with positive Coombs test, IgM+C type. Elution of antierythrocyte antibodies did not enable us to identify any specificity. Haemolysis lasted 45 days before haemoglobin slowly increased after CsA had been greatly reduced. Direct antiglobulin tests remained positive 5 months after transplantation and became negative the following month. Eight months after the transplantation the patient had a normal haemoglobin level and normal renal function. Although the typing of autoantibodies was not possible, our data suggest that this patient's haemolysis may be related to the clonal development of donor B lymphocytes in the recipient, favoured by an HLA A-B-DR identity and post-transplant CsA therapy, as exceptionally reported in the literature.