Iron is essential for cellular functions, but in excessive amounts it is toxic to cells. The harmful effects are related to increased oxidative stress and production of reactive oxygen species causing oxidative damage to lipids, proteins, and nucleic acids. Heavy iron overload as occurs in primary and secondary hemochromatosis can cause fibrosis of various parenchymal organs such as the liver, heart, and pancreas. Lesser degrees of hepatic iron deposition are also associated with, and seem to be risk factors for, certain nonhemochromatotic liver diseases. Porphyria cutanea tarda is associated with hepatic iron overload and responds to iron-reduction therapy. Other recent evidence indicates that the prevalence of HFE gene mutations is increased in chronic viral hepatitis and that patients with chronic hepatitis C harboring especially the C282Y mutation are more likely to suffer from advanced hepatic fibrosis or cirrhosis and to do so at younger ages. In this article we review selected nonhemochromatotic disorders in which iron can play an important comorbid role.