We studied the effect of Helicobacter pylori (H. pylori) eradication in 43 consecutive H. pylori-infected patients with idiopathic thrombocytopenic purpura. H. pylori was eradicated with antibiotics in 41 of them (95.3%). The difference between the mean platelet count before and after therapy was statistically significant (54.3 x 10(9)/l vs. 119.1 x 10(9)/l; P < 0.001). A sustained remission was observed in 20 patients (48.8%), after a median follow-up of 31.2 months. None of the patients still infected by H. pylori after therapy reached normal platelet values. The long-term follow-up confirms the efficacy of H. pylori eradication in H. pylori-infected ITP patients.