Background: Oral Ferric Citrate (FC) is an effective iron therapy in hemodialysis patients. We investigated the effect of oral iron on anemia in hemodialysis patients focusing on different effects between sodium ferrous citrate (SF) and FC and dose effect of SF.Methods: Study 1; FC was administered (1500 mg/day) either as a de novo iron administration (Group D) or after a switch from SF (50 mg/day) (Group S). Dose of erythropoietin stimulating agent (ESA), serum hemoglobin levels, ESA/hemoglobin ratio and iron states were investigated for 64 weeks retrospectively. Study 2; 23 stable hemodialysis patients with long-term 50 mg/day of SF were randomly divided to two groups; dose was increased to 150 mg/day (Group 150) and unchanged in the rest (Group 50). Without changing the dose of ESA, hemoglobin levels and iron states were compared for 40 weeks prospectively. Results: Study 1; data were obtained from 28 patients. FC administration increased ferritin levels in both groups (median; Group D; 0W: 49.3, 56W: 214.0, Group S; 0W: 120.0, 56W: 217.0 ng/mL), but hemoglobin levels increased and ESA dose and ESA/hemoglobin ratio decreased only in Group D (0W vs. 12W: p < 0.05). Study 2; 17 patients completed the study. Although higher dose of SF resulted in increased ferritin and hepcidin-25 levels in Group 150 (p < 0.05 and < 0.01, respectively), hemoglobin levels did not change in either group.Conclusions: Instable hemodialysis patients, 50 mg/day of SF have a comparable effect on anemia to that of 1500 mg/day of FC or 150 mg/day of SF with less increase in serum ferritin levels.