Background. Intravenous (i.v.) iron sucrose similar (ISS) preparations are available but clinical comparisons with the originator iron sucrose (IS) are lacking.Methods. The impact of switching from IS to ISS on anaemia and iron parameters was assessed in a sequential observational study comparing two periods of 27 weeks each in 75 stable haemodialysis (HD) patients receiving i.v. iron weekly and an i.v. erythropoiesis-stimulating agent (ESA) once every 2 weeks. Patients received IS in the first period (P1) and ISS in the second period (P2).Results. Mean haemoglobin value was 11.78 ± 0.99 g/dL during P1 and 11.48 ± 0.98 g/dL during P2 (P = 0.01). Mean serum ferritin was similar for both treatment periods (P1, 534 ± 328 μg/L; P2, 495 ± 280 μg/L, P = 0.25) but mean TSAT during P1 (49.3 ± 10.9%) was significantly higher than during P2 (24.5 ± 9.4%, P <0.0001). The mean dose of i.v. iron per patient per week was 45.58 ± 32.55 mg in P1 and 61.36 ± 30.98 mg in P2 (+34.6%), while the mean ESA dose was 0.58 ± 0.52 and 0.66 ± 0.64 μg/kg/week, respectively (+13.8%). Total mean anaemia drug costs increased in P2 by 11.9% compared to P1.Conclusions. The switch from the originator IS to an ISS preparation led to destabilization of a well-controlled population of HD patients and incurred an increase in total anaemia drug costs. Prospective comparative clinical studies are required to prove that ISS are as efficacious and safe as the originator i.v. IS.