The development of anemia in patients with chronic obstructive pulmonary disease (COPD) is now taken as a predictor of increased morbidity and mortality. Preliminary data from patients investigated in our department indicate a negative correlation between anemia severity and 6-minute walking distance. Our working hypothesis is that hemoglobin level correction by erythropoietin therapy will improve the effort capacity of patients with COPD and anemia. Our objective is to conduct a pilot study of the efficacy of darbepoetin alfa.