Hereditary hemochromatosis (HH) is an autosomal recessive disease in which increased iron absorption causes iron overload and irreversible tissue damage. As laboratory parameters for measuring HH lack specificity, and HH remains asymptomatic for a long time, methods for genetic screening are highly valuable. Mutations in two genes, hfe and TfR2, have recently been found to be responsible for HH. The mutation C282Y in the hfe gene is detected in 70-95% of German and Austrian HH patients. Mutations in the TfR2 gene have been detected only very recently, and results of larger epidemiological studies are not yet available. Molecular methods permit molecular diagnosis and genetic screening.