In populations of northern European descent, the p.C282Y mutation in the HFE gene is highly prevalent, and HFE-associated hereditary hemochromatosis is the most common type of inherited iron overload disorder. Inappropriate low secretion of hepcidin, which negatively regulates iron absorption, is postulated to be the mechanism for iron overload in this condition. The characteristic biochemical abnormalities are elevated serum transferrin-iron saturation and serum ferritin. Typical clinical manifestations include cirrhosis, liver fibrosis, hepatocellular carcinoma, elevated serum aminotransferase levels, diabetes mellitus, restrictive cardiomyopathy and arthropathy of the second and third metacarpophalangeal joints. Most patients are now diagnosed before the development of these clinical features. Molecular genetic tests are currently available for genotypic diagnosis. In selected individuals, diagnosis might require liver biopsy or quantitative phlebotomy. Iron depletion by phlebotomy is the mainstay of treatment and is highly effective in preventing the complications of iron overload if instituted before the development of cirrhosis. Genetic testing is currently not recommended for population screening because of low yield as the majority of the healthy, asymptomatic p.C282Y homozygotes do not develop clinically significant iron overload. HFE gene testing remains an excellent tool for the screening of first-degree relatives of affected probands who are p.C282Y homozygotes.