This report describes the potential and actual effects that recombinant human erythropoietin (rHuEpo) may have on the practice of renal transplantation. Three aspects are highlighted. The first is the effects in the dialysis patient transplanted after treatment with rHuEpo. These include the potential risks of graft thrombosis and prolonged initial nonfunction (for which there is little supportive evidence), and the impact on pretransplant immune-modulating regimens, which take advantage of the so-called transfusion effect. As the importance of this effect to overall graft survival has diminished strikingly, this may be of little consequence. The second aspect relates to the highly presensitized dialysis patient. The literature and our own data are presented, showing the beneficial effects of rHuEpo therapy on reducing the level of humoral anti-HLA sensitization. This may lead to benefits that include reduced time on the waiting list for a cadaveric renal transplant, and possibly improved allograft survival. Finally, our data on the use of rHuEpo in 13 patients with anemia (usually due to chronic graft failure) after transplantation is discussed. rHuEpo therapy was effective in all patients, leading to reversal of anemia. Side effects, including hypertension and hypertensive seizures, occurred in the subgroup of patients with significant renal dysfunction (serum creatinine greater than 2.5 mg/DL).