Hereditary haemochromatosis is an under-diagnosed and treatable cause of chronic liver disease. Its prevalence indicates that selective population screening may be worthwhile, but opinion differs as to whether diabetic patients constitute such a group. We studied 727 patients attending a teaching hospital diabetic clinic. On first testing, 7.4% had abnormally high iron indices, but only 3% remained abnormal on retesting. Of these patients, those at high risk were offered liver biopsy for histological assessment and iron assay. Only one had hereditary haemochromatosis, but all had abnormal liver histology--largely steatosis but some with fibrosis. These findings raise questions regarding the true prevalence of this disorder in North-East England, do not indicate that targeted screening of diabetic patients is worthwhile, and incidentally highlight the potential importance of diabetes as a cause of liver disease.