While classical hereditary haemochromatosis, usually associated with mutations in the HFE gene, has an adult age onset and a long, progressive evolution, juvenile haemochromatosis, most often associated with mutations in the HJV gene, is a more severe, rapidly progressive condition and has an onset before the age of 30. We report a 26-year old woman with a severe iron overload, affected by hypogonadotropic hypogonadism and moderate dilative cardiomyopathy, in whom the molecular analysis revealed a homozygous genotype for G320V mutation in the HJV gene. As juvenile haemochromatosis is a severe disease, death usually occurring from cardiac involvement, an efficient iron removal from the body strategy should be started as soon as possible, in order to prevent irreversible damage.