Continuous erythropoietin receptor activator (CERA) and darbepoetin-α (DA) might differently affect iron metabolism and erythropoiesis in patients on hemodialysis (HD). This prospective study examined a cohort of patients on HD who had received either intravenous CERA every 2 or 4 weeks (N = 25) or DA once each week (N = 47). Blood was sampled before HD sessions on days 0, 2, 4, 7 and 14, and on days 0, 3, 5, 7 and 14 from patients who were injected with ESA at the beginning and end of the dialysis week, respectively. Changes in factors indicating erythropoiesis and biomarkers of iron metabolism were examined. Hemoglobin levels were maintained in the target range between 10.0 and 11.0 g/dL and ferritin levels at baseline and during the study period were similar between the DA and CERA groups. Levels of hepcidin 25 decreased from days 2–3 to day 5 and returned to the baseline at day 7 in the DA group, whereas those and transferrin saturation were serially suppressed from days 2–3 to day 14 in the CERA group. Levels of soluble transferrin receptor and reticulocyte counts were significantly elevated from days 4–5 to day 14 by CERA. Both DA and CERA stabilized erythropoiesis, but CERA might mobilize iron from body stores more effectively than DA in patients on HD.