A man with a 20-year history of recurrent iron-deficiency anemia complicated by Helicobacter pylori-positive Ménètrier's disease was observed over a 10-year clinical course, during which time he was successfully treated for the anemia and a gastric Helicobacter pylori (H. pylori) infection through eradication. Considering the satisfactory therapeutic results in this case, we performed eradication therapy on another H. pylori-positive atrophic gastritis case with a 24-year history of iron-deficiency anemia of unknown etiology, and again, complete remission was obtained. The clinical evidence from these two cases suggests that the gastric H. pylori infection was deeply involved in the pathogeneses of the iron-deficiency anemia. We believe that these case reports will provide useful information on H. pylon-involved pathology in the fields of hematology and gastroenterology.