Abstract Hereditary hemochromatosis (HH) is a common autosomal recessive disorder estimated to affect one out of every 250–400 Caucasian individuals. It is a disorder of iron metabolism, in which excessive iron accumulation in the body may induce serious clinical manifestations (e.g. liver cirrhosis, hepatocellular carcinoma, diabetes, and cardiomyopathy). HH is caused by mutations in the HFE gene, and HFE genotyping thus enables early diagnosis of the disease and detection of the individuals at risk for HH. HFE mutations have also been proposed to predispose to certain other diseases, such as various hematological malignancies and cardiomyopathy. The present evaluation of the clinical utility and outcome of HFE genotyping in search for HH was based on data obtained from 137 subjects referred for HFE mutation analysis during the years 1999–2001. The C282Y and H63D mutations were determined for each subject. HFE genotyping was also used to examine the association between HFE mutations with various hematological disorders and idiopathic dilated cardiomyopathy (IDCM). The C282Y and H63D mutations were determined from 232 patients with various hematological disorders and the C282Y, H63D, and S65C mutations from 91 patients with IDCM and 102 control subjects. High frequencies of C282Y homozygotes (16.8%) and C282Y/H63D compound heterozygotes (5.1%) were found among the subjects referred for HFE genotyping, and the rate of positive findings for HH increased steadily over the years 1999–2001. The frequencies of HFE mutations did not differ significantly in patients with various hematological disorders and IDCM compared to controls. At the end of the follow-up period, left ventricular end-diastolic diameter (LVEDD) was significantly higher in IDCM patients carrying the C282Y mutation than in those without this mutation (p = 0.037). The present study supports active testing for the HFE gene mutations C282Y and H63D in public health care. Serum transferrin saturation is considered the most useful test for selecting subjects for such analysis. Although increasing numbers of HH cases are recognized by physicians, it may still be an underdiagnosed disease. HFE mutations do not seem to significantly increase the risk for various hematological disorders or IDCM. The C282Y mutation may, nevertheless, mediate the progression of IDCM by modifying LV dilation and remodeling.