Unresponsiveness to erythropoiesis-stimulating agents is a major limitation to the treatment of chemotherapy-related anemia. This is often related to a disregulation of iron metabolism leading to functional iron deficiency. However, the use of iron supplementation during treatment with erythropoiesis-stimulating agents has not been as rigorously pursued in anemic patients with cancer as it has in chronic kidney disease. In this article, we review and discuss the role of iron supplementation in the setting of chemotherapy-related anemia in view of recently published clinical trials addressing this issue. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]