The excessive storage of iron in idiopathic haemochromatosis leads to severe organic lesion up to life-threatening conditions (cardiac insufficiency, portal decompensation). The symptoms melanodermia , diabetes mellitus and other endocrine failures, liver cirrhosis, cardiac insufficiency and arthropathy appear together or in various combinations. The diagnosis is ascertained by the proof of iron storage, the multiple organic affection and by familial accumulation of the various laboratory diagnostic possibilities are particularly to be emphasized the serum iron value together with the percetal transferrin saturation (as search test), serum ferritin, the desferrioxamine test, simple ferrokinetic investigations and the quantitative determination of iron in the liver in the bioptate . For family examinations, apart from the search test, a HLA typisation is reasonable, in order to estimate the risk of the disease (particularly of brothers and sisters). The therapy of choice are blood- lettings (0.5 l once to twice a week) up to obtaining a permanent easy iron deficiency anaemia. The maintenance therapy should be performed with monthly to quarterly blood- lettings . Only in cases exception a desferal treatment is indicated. Endocrine failures and cardiac disturbances need a particular therapy.