Objective: To explore a possible association between Helicobacter pylori infection and iron status. Design: Cross-sectional study. Setting: Ballarat (a major regional city in Victoria), population 78 000, October November 1997. Participants: 160 women and 152 men, a subsample of participants in a cardiovascular disease risk factor prevalence survey for whom frozen plasma was available. Main outcome measures: H. pylori IgG antibody status by enzyme immunoassay; iron intake; plasma iron, transferrin and ferritin concentrations. Results: 28% of women and 33% of men were infected with H. pylori. The mean (SEM) plasma ferritin concentration of infected women (59.3 [7.6] mu g/L) was significantly lower than for non-infected women (88.8 [7.9] mu g/L; P=0.002), after adjusting for age. Mean daily dietary iron intakes were similar in infected and noninfected women. Conclusions: H. pylori infection appears to be an additional stressor on women's iron status, but the mechanism remains to be determined.