Background Intravenous (IV) iron preparations bypass the difficulties (malabsorption and side effects) associated with oral iron for the treatment of iron deficiency anaemia (IDA). Ferric carboxymaltose (FCM) can be administered as a single infusion over short periods of time but is more expensive than iron sucrose (IS) when the patients are hospitalized. Objectives To evaluate the appropriateness of FCM prescriptions and to establish the economic impact of this management (including disease coding) compared to the use of IV IS. Setting This study was conducted for inpatients in all departments (orthopaedic department, gastroenterology department and two units of the internal medicine department) where FCM was widely prescribed. Method We retrospectively identified 224 patients, diagnosed with IDA using laboratory parameters and/or disease coding, who received FCM between January and December 2014. Main outcome measure The primary outcome was the rate of appropriateness of FCM prescriptions and the financial impact compared to IV IS. Results 89 Patients were included. The total additional cost for an inappropriate prescription of IV FCM (68% of cases) was of 6053 €. The total incremental cost of unsuitable disease coding was estimated at 31,688 €. Indications for IV FCM were categorized: intestinal bleeding (31%), malabsorption (17%), intolerance (9%) and refractory to oral iron (7%). The majority of patients (62%) received 1000 mg of FCM per week. The average length of hospital stay was of 10 days. Conclusion The prescription of IV iron was appropriate in most cases but did not necessarily require FCM. The use of IV IS, in many cases, could present a cost-saving option for inpatients with IDA. The lack of an IDA coding generated incremental costs.