Although hereditary hemochromatosis is an autosomal recessive disease, most homozygotes are concerned with the genetic implications for their children. The optimal age for testing children and the cost implications of screening their children have not been clearly established. A clinical database consisting of 255 children from families with at least one homozygote is used to assess the prevalence of homozygotes among children of homozygous parents and to review the biochemical abnormalities and life-threatening symptoms in these young adults. Decision analysis is used to estimate the cost and utility of screening children of a homozygous parent. Eleven homozygotes were discovered among children of homozygotes. Only one male had a life-threatening event, cirrhosis. Decision analysis estimated cost saving of $12 per child screened ($ net present value) and a saving of 10 quality-adjusted days per child screened at age 10 years compared with not screening. If screening began at age 20 years, there is a cost saving of $65 per child screened. Sensitivity analysis showed that the major factors influencing cost savings were the cost of venesections, sensitivity and specificity of the screening tests, and prevalence of disease. Because the prevalence of hemochromatosis is higher in children of homozygotes than in the general population, screening with transferrin saturation and ferritin as early as age 10 years is recommended. Savings are augmented if the cost per venesection is eliminated by allowing hemochromatosis patients to become voluntary blood donors.