BACKGROUND: Iron deficiency anemia is the most common form of anemia worldwide. Recent studies have suggested an association between Helicobacter pylori infection and iron deficiency. OBJECTIVE: To investigate the effects of eradicating H. pylori with combination antibiotic therapy on iron deficiency anemia in patients with H. pylori-associated gastritis. DESIGN: Case series. SETTING: University hospital. PATIENTS: 30 patients with a long history of iron deficiency anemia in whom H. pylori-associated gastritis was the only pathologic gastrointestinal finding detected. INTERVENTION: Eradication therapy with two antibiotics and discontinuation of iron replacement therapy. MEASUREMENTS: Complete blood count, ferritin levels, and gastroscopy with biopsy to evaluate H. pylori status. RESULTS: At 6 months, 75% of patients had recovered from anemia (P<0.001), ferritin values increased from 5.7+/-0.7 microg/L to 24.5+/-5.2 microg/L (95% CI, 8.85 to 29.97). After 12 months, 91.7% of patients had recovered from anemia. CONCLUSIONS: Cure of H. pylori infection is associated with reversal of iron dependence and recovery from iron deficiency anemia.