There is still controversy concerning the optimal target hemoglobin during treatment with recombinant human erythropoietin (rHuEPO). Some evidence suggests that hemoglobin concentrations higher than currently recommended lead to improvements in cognitive function, physical performance, and rehabilitation. At least in patients with advanced cardiac disease, however, one controlled trial failed to show a benefit from normalizing predialysis hemoglobin concentrations. In contrast, preliminary observations in three additional studies (albeit with limited statistical power) failed to show adverse cardiovascular effects from normalization of hemoglobin, but definite benefit with respect to quality of life, physical performance, and cardiac geometry. These observations are consistent with the notion that hemoglobin concentrations higher than those recommended by the National Kidney Foundation Dialysis Outcomes Quality Initiative Anemia Work Group are beneficial, at least in patients without advanced cardiac disease.