It has been suggested that excess iron may facilitate the occurrence of cancer. Patients with hereditary hemochromatosis (HH) are at high risk of developing liver cancer, and studies of limited series reported a high frequency of nonhepatic cancers. To verify whether patients with HH are at higher risk of liver cancer and other malignancies as compared with patients with non-iron-related chronic liver disease (CLD), we analyzed the occurrence of neoplasms in 230 patients with HH and 230 with non-iron-related CLD. The patients were matched by sex, age, duration of follow-up (+/-5 years), and severity of liver disease. On enrollment, the following variables were considered: hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, alcohol abuse, smoking, and a family history of cancer (first-degree relatives). The diagnosis of primary cancers was confirmed by histology. During the follow-up, hepatocellular carcinoma (HCC) developed in 49 and 29 patients (all cirrhotic patients) with HH and non-iron-related CLD, respectively, with a relative risk of 1.8 (95% confidence interval [CI] 1.1-2.9); nonhepatic cancers occurred in 20 and 11 patients, respectively, with a relative risk of 1.8 (95% CI 0.8-4). Four patients with HH and 1 with non-iron-related CLD developed 2 different primary cancers during follow-up. The risk of cancer after adjustment for alcohol abuse, smoking, and family history of cancer was 1.9 (95% CI 1.1-3.1) in the patients with HH. In conclusion, patients with HH are at high risk of both liver cancer and other malignancies, which should be carefully sought during follow-up.