Iron overload is the principal cause of morbidity and mortality in β‐thalassemia with or without transfusion dependence. Iron homeostasis is regulated by the hepatic peptide hormone hepcidin. Hepcidin controls dietary iron absorption, plasma iron concentrations, and tissue iron distribution. A deficiency in this hormone is the main or contributing factor of iron overload in iron‐loading anemias such as β‐thalassemia. Hepcidin deficiency results from a strong suppressive effect of the high erythropoietic activity on hepcidin expression. Although in thalassemia major patients iron absorption contributes less to the total iron load than transfusions, in non‐transfused thalassemia, low hepcidin, and the consequent hyperabsorption of dietary iron is the major cause of systemic iron overload. Hepcidin diagnostics and future therapeutic agonists may help in management of patients with β‐thalassemia.