Experience over the last 20 years with 34 patients with idiopathic hemochromatosis is summarized and the literature is reviewed. Methods are now available which are highly effective in the diagnosis of iron overload and virtually all diagnoses are made antemortem. The nature of the disease has changed through the removal of iron by phlebotomy. Early deaths are limited to patients with severe and rapidly progressive heart disease and to those presenting with neoplasm. The major mortality has shifted to a much later period and the incidence of hepatoma is increasing. There is particular interest at the present time in family studies since excessive iron stores are frequently found within the family. The significance of intermediate degrees of iron overload is unclear, but future attention should be given to the recognition of iron overload long before clinical manifestations appear.