The aim of our present work was to collect data on HLA distribution in patients with idiopathic haemochromatosis in Hungary. Ten unrelated patients with idiopathic haemochromatosis (6 men, 4 women) were studied. Idiopathic haemochromatosis was diagnosed on clinical, biochemical and histological grounds. HLA typing was performed in 10 probands and in all of their first degree relatives available (24) through 7 pedigree studies. HLA A3 was present in 6 of 10 probands [6/10 vs. 18.8% in the group of healthy blood donors (No 53) and 22.4% in Hungarian population (No 1910]. HLA B7 was present in 4 of 10 probands (40% vs. 11.3% and 14.6%). A3B7 antigen association has been found in 4 of 10 patients. A3B7 and A2B38 haplotypes were present twice in 4 of 7 genotyped probands. Pedigree studies revealed one nonaffected homozygote, 17 heterozygotes and 6 non carriers. Extended family and population studies are necessary to establish the gene frequency in Hungary and the probability of the involved haplotypes other than A3B7.