Parenteral iron treatment is used especially in patients who need urgent treatment, have intolerance symptoms to oral iron therapy, and/ or where therapy with oral iron supplementation is insufficient. Allergic reactions can be observed with intravenous iron containing medicines and they should thus only be administered by trained staff with appropriate resuscitation facilities. The European Medicines Agency does not approve the use of intravenous iron-containing products in patients with previous hypersensitivity reactions to other parenteral iron products in its 2013 recommendations to manage the risk of allergic reactions to intravenous iron-containing medicines. However, it may be an option to administer intravenous iron therapy with desensitization in patients who need urgent treatment, who cannot be treated effectively with oral iron preparations, or display intolerance to these products. Here we present the first case of successful ferric carboxymaltose desensitization in a patient who had suffered a prior reaction with the same medicine.