PURPOSE: The aim of this multicenter prospective study was to evaluate efficacy and safety of biosimilar erythropoiesis-stimulating agents (ESAs) vs originator, based on data from clinical practice in patients with chronic kidney disease (CKD). METHODS: We collected data of the patients with diagnosis of CKD on conservative treatment from nine Italian structures. Patients were enrolled applying different exclusion criteria, and various individual parameters were registered at the beginning for descriptive analysis. Patients were treated with epoetin alfa, beta, and darbepoetin as originator and epoetin zeta as biosimilar. Hemoglobin levels have been analyzed at baseline and after 3, 6, and 12 months. Descriptive statistics were used to analyze the results. RESULTS: At baseline, 47 patients were in the biosimilar group and 57 in the originator; the basal level of hemoglobin was similar between the groups (mean Hb 9.4 and 9.3 g/dL, respectively). Median age, weight, and comorbidities were almost comparable. After 3 months, 44 patients remained in the biosimilar group and 48 in the originator; hemoglobin increase was significantly greater in patients treated with biosimilar [absolute increase 1.6 vs 1.0 g/dL, p < 0.001]. After 6 and 12 months, number of patients fall furthermore. Hemoglobin levels increased more in the biosimilar group after 6 months (2.1 vs 1.1 g/dL, p < 0.001) and 12 months (2.0 vs 1.0 g/dL, p < 0.001). CONCLUSIONS: Biosimilar ESAs have similar risk/benefit profile compared to originators. Our data are in agreement with relevant scientific literature and, on the other hand, they are in contrast with common thought that considers biosimilar less efficacious and less safe than originators.