Initial clinical trials with recombinant human erythropoietin provided evidence of a quality-of-life benefit for patients with anemic end-stage renal disease who received maintenance hemodialysis. As part of a phase III clinical trial of recombinant human erythropoietin, the quality of life of patients was systematically assessed. More than 300 patients at nine dialysis centers were evaluated. A statistically significant improvement was established between baseline and second follow-up on most objective and subjective quality-of-life parameters, including energy and activity level, functional ability, sleep and eating behavior, disease symptoms, health status, satisfaction with health, sex life, well-being, psychological affect, life satisfaction, and happiness. No change was observed in ability to work or employment status. We conclude that, in addition to substantial improvement in hematologic parameters, recombinant human erythropoietin greatly enhances the quality of life of anemic patients who receive maintenance hemodialysis.