As the importance of recombinant human erythropoietin (r-HuEPO) therapy has been clearly demonstrated in anaemic patients with chronic renal failure (CRF), we carried out an open, non-randomized, non-placebo-controlled trial of high-dose intravenous (i.v.) r-HuEPO (100,000 U twice weekly) therapy in 14 anaemic, transfusion-dependent patients. Clinical response was defined by a rise in haemoglobin concentration to 9-11 g/dl and/or a reduction in the transfusion requirement during the treatment period compared with the 12 weeks before treatment. Eight patients completed the 12-week treatment and 4 were still under treatment, 1 at 10 weeks, 2 at 8 weeks and 1 at 4 weeks. Only those patients completing treatment were included in the efficacy evaluation. After treatment there was no significant change in haemoglobin concentrations, reticulocyte counts, or transfusion requirements. However, the number of patients included is too low to allow any definitive conclusion to be made.