The authors compared the amount of hepatic parenchymal cell stainable iron in 159 hemochromatosis homozygotes. They were separated into four groups. Group 1: 59 symptomatic hemochromatosis probands with hemochromatosis (mean age 49 years) who were identified because of symptoms and signs of iron overload. Group 2: 38 asymptomatic probands with hemochromatosis (mean age 29 years) identified during population screening studies or during routine health maintenance evaluation. Group 3: 47 homozygous relatives (mean age 43 years) of Group 1 probands. Group 4: 15 homozygous relatives (mean age 30 years) of Group 2 probands. The symptomatic probands (Group 1) were 20 years older and had much more stainable hepatic iron (p < 0.0001) than the asymptomatic probands (Group 2). The homozygous relatives (Group 3) of the symptomatic probands also were older and had much more stainable hepatic iron than the homozygous relatives (Group 4) of asymptomatic probands (p < 0.0002). The results of this study suggest that population screening studies can result in early identification of individuals with hemochromatosis before massive hepatic iron overload occurs and before symptoms of iron overload develop.