This prospective, multicenter, observational study will evaluate the impact of comorbidity factors on the hemoglobin level in participants with chronic kidney disease who are not on dialysis and initiated on treatment with methoxy polyethylene glycol-epoetin beta (Mircera). Data will be collected for 9 months after initiation of methoxy polyethylene glycol-epoetin beta treatment.

Inclusion Criteria:

• Participants with chronic kidney disease not on dialysis
• Treatment-naïve for erythropoiesis-stimulating agents (ESAs), not having received ESAs in the 6 months prior to inclusion in this study
• Hemoglobin level less then (<)10 grams per deciliter (g/dL) at inclusion
• Participants for whom the treating physician has decided to initiate treatment with methoxy polyethylene glycol-epoetin beta for medical reasons prior to study start

Exclusion Criteria:

• Functional renal transplant
• Current participation in a clinical trial in anemia due to chronic kidney disease

ESA naïve participants with chronic kidney disease who are not on dialysis