This single arm study will assess the efficacy and safety of subcutaneous Mircera for the correction and maintenance of hemoglobin levels in predialysis patients with renal anemia who are not currently treated with ESA. Eligible patients will receive monthly subcutaneous injections at an initial recommended dose of 1.2 micrograms/kg. The anticipated time on study treatment is 3-12 months, and the target sample size is 100-500 individuals.