Helicobacter pylori infections are associated with iron deficiency, even in the absence of bleeding. To determine whether H. pylori infection plays a role in modifying the phenotype of patients homozygous for the c.845 G > A (C282Y) mutation of the HFE gene we studied 79 homozygous women and 76 homozygous men, comparing the pretreatment hemoglobin, MCV, serum ferritin, transferrin saturation of those who were seropositive and seronegative for H. pylori. No difference between seropositive and seronegative homozytoes was found. There was also no difference between seropositive and seronegative control subjects. We also compared the total iron of 56 of the male and 32 of the female homozygotes as determined by serial phlebotomy. No significant difference was found.