This single arm study will evaluate the hemoglobin (Hb) increasing effect, safety and tolerability of two-weekly intravenous administration of Mircera in dialysis patients with chronic renal anemia not currently treated with ESAs. Patients will receive intravenous Mircera 0.6 micrograms/kg every 2 weeks for 16 weeks with follow up 2 weeks after the last treatment visit. The anticipated time on study treatment is 3-12 months, and the target sample size is 100-500 individuals.