['DNA-based HFE gene testing can confirm hereditary hemochromatosis in most people of Northern European descent. However, liver biopsy is important to detect cirrhosis.', 'To develop noninvasive criteria to predict the presence or absence of advanced hepatic fibrosis or cirrhosis in Americans with hemochromatosis.', 'Cross-sectional study.', 'Six tertiary care referral clinics.', '182 patients with phenotypically defined hemochromatosis.', 'Liver histopathology and serum ferritin, aspartate aminotransferase, and alanine aminotransferase levels. Multivariate logistic regression analysis was used to examine factors associated with cirrhosis (defined as bridging fibrosis or unequivocal cirrhosis on biopsy).', 'Cirrhosis was present in 40 of 182 (22%) patients in the overall group and in 35 of 147 (24%) of C282Y homozygotes. Only 1 of 93 patients with a serum ferritin level less than 1000 microg/L had cirrhosis compared with 39 of 89 patients with serum ferritin levels greater than 1000 microg/L (P < 0.001). No C282Y homozygotes or C282Y/H63D compound heterozygotes with serum ferritin levels less than 1000 microg/L had cirrhosis. Elevated serum aminotransferase levels (P = 0.001) and serum ferritin levels greater than 1000 microg/L (P = 0.001), but not age older than 40 years (P = 0.2), were independently associated with cirrhosis. In a multivariate model, the probability of cirrhosis was 7.4% among patients with serum ferritin levels less than 1000 microg/L compared with 72% among patients with serum ferritin levels greater than 1000 microg/L after adjustment for age and elevated serum liver enzyme levels.'] Does serum ferritin level predict advanced hepatic fibrosis among U.S. patients with phenotypic hemochromatosis?