To evaluate the effect of recombinant human erythropoietin on anemia and health-related quality of life in patients with acquired immunodeficiency syndrome (AIDS), we initiated an observational study with an open-label multicenter treatment protocol that involved multiple academic and community physicians in the United States. Our subjects comprised 251 anemic (i.e., hematocrit < 30%) patients with a clinical diagnosis of AIDS using 1987 CDC criteria, age ≥ 12 years, and serum erythropoietin level ≤500 IU/L. The initial dosage of recombinant human erythropoietin was 4,000 units subcutaneously for 6 days each week. Based on the patient's response to therapy, the dosage was increased sequentially to 8,000 units subcutaneously for 6 days per week. Our measurements included changes in mean hematocrit and health-related quality of life. The interview included measures of energy/fatigue; physical, social, role and cognitive function: depression; health perceptions; and life satisfaction. Adverse experiences were also documented to assess safety. Changes in mean hematocrit level from a baseline of 27.9% to 33.6% at week 12 (p < .0001) and 34.5% at week 24 (p < .0001) were observed in patients treated with recombinant human erythropoietin. Adverse experiences, not clearly associated with AIDS, were reported by 10% of patients. Increases in energy (p < 05) were observed after 12 and 24 weeks of drug therapy, and increases in health perceptions were seen after 24 weeks (p < .05). No statistically significant increases or decreases were observed on measures of physical functioning, cognitive functioning, depression, social functioning, or home management activities over the 24-week follow-up. Anemia correctors (defined as hematocrit ≥38%) showed greater improvement in energy, health perceptions, home management, and role function than noncorrectors. Study dropouts and those who died had significantly worse scores for health-related quality of life at baseline compared to study completers. Thus, the AIDS patients with anemia and serum erythropoietin levels ≥500 IU/L treated with recombinant human erythropoietin showed increased mean hematocrit and improved health perceptions and energy levels. The drug therapy was associated with increased feelings of energy, but it was not associated with other changes in health status and well-being in the AIDS patients completing the study. These observations need to be confirmed in randomized clinical trials.