We evaluated the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in 78 Italian patients with hereditary hemochromatosis as well as the relation between HCV antibody (anti-HCV) status, hepatitis B surface antigen (HBsAg) and liver histology. None of the patients had been transfused or ever consumed more than 60 g of alcohol per day. Eighteen showed histological signs of chronic hepatitis, active cirrhosis was present in 12, chronic active hepatitis in 4 and chronic persistent hepatitis in 2. Liver fibrosis or cirrhosis without inflammatory activity was observed in 31 subjects, whereas liver histology was normal except for iron overload in 18. The prevalence of HBsAg in the whole series was 5% and of anti-HCV was 20.5%. The prevalence of HBsAg and anti-HCV was significantly higher in the chronic hepatitis group than in the fibrosis/cirrhosis (p = 0.01) and the normal groups (p < 0.01). Fourteen of 18 hereditary hemochromatosis patients with chronic hepatitis were HBsAg (4) or anti-HCV (10) positive and all the latter subgroup had HCV-RNA in their serum as shown by the polymerase chain reaction. Although most of the patients with associated chronic hepatitis had cirrhosis, their serum ferritin levels and amount of mobilizable iron were significantly lower than those of the fibrosis/cirrhosis group (p < 0.01). This indicates that hepatitis viral infection acts synergistically with iron in accelerating the development of liver damage.