Background/Aims: Hereditary hemochromatosis (HH), the most common autosomal recessive disease in the white population, is characterized by excessive gastrointestinal absorption of iron and loading of parenchymal organs. HFE mutations of C282Y and H63D are largely responsible for HH in populations of Celtic ancestry. Although many screening studies related to HH have been done in Northern Europe, the USA and Australia, as yet, no such study has been published on Turkey. In this study we aimed to screen the Turkish population for iron overload. Methods: Random samples were obtained from 4,633 healthy adults (3,827 male, 806 female, mean age+/-SD 35+/-8 years, range 14-76) for the measurement of transferrin saturation (TS). Measurements were repeated after an overnight fast in the subjects whose initial TS was greater than or equal to50%. Serum ferritin levels and C282Y and H63D gene mutations were studied in cases when fasting TS was greater than or equal to50%. In cases where the serum ferritin level was >200 ng/ml with or without HFE mutations, liver biopsy was performed for histological evaluation and determination of iron content. Results: In 158 subjects, TS was greater than or equal to50% in the non-fasting state. A second determination of TS after an overnight fast was performed in 135 subjects. In 26 subjects, the TS was greater than or equal to50% in the fasting state. HFE mutation and serum ferritin levels were measured in these 26 subjects. Eleven subject (10 male, 1 female) were heterozygote and 1 male subject was homozygote in reference to H63D. C282Y mutation was not found. Four of these 26 subjects (all males, aged 23, 24, 40, 49) had increased serum ferritin levels and liver biopsy was performed. In 1 male (aged 49) who was heterozygote for H63D genotype with a serum ferritin level of 645 ng/ml, iron overload in liver tissue was shown by histology as well as atomic absorption spectrophotometry. Conclusion: The prevalence of hemochromatosis in the Turkish population is much lower in comparison to populations of Celtic ancestry and C282Y mutation is non-existent. Copyright (C) 2003 S. Karger AG, Basel.