BACKGROUND AND OBJECTIVES: There are data consistent with an association between idiopathic thrombocytopenic purpura (ITP) and Helicobacter pylori (HP) infection. In addition, a significant increase of platelet count following HP eradication has been reported in a proportion of ITP patients. We describe here our experience on the efficacy of anti-HP treatment in ITP patients. DESIGN AND METHODS: Between December 1998 and May 2001 sixteen adult patients with ITP and documented HP infection were treated with standard antibiotic therapy for HP eradication (amoxicillin and clarithromycin plus pantoprazole combination). Of these patients, 7 had untreated ITP with mild/moderate thrombocytopenia (median platelet count 70x10(9)/L, range 41-91), 5 had relapsed following a previous steroid treatment (median platelet count 39x10(9)/L, range 30-90) and 4 were refractory to steroids (median platelet count 18.5x10(9)/L, range 9-30). RESULTS: An improvement of platelet count was observed in 11/15 patients (73.3%) who achieved HP eradication. The difference between the mean platelet count SD before and after HP eradication was statistically significant (51.6 28.2x10(9)/L vs. 143.3 131.1x10(9)/L; p=0.01). Complete or partial responses were obtained in 11/16 treated patients (68.7%). This result still persisted after a median follow-up of 11.7 months. INTERPRETATION AND CONCLUSIONS: Our data confirm the efficacy of Helicobacter pylori eradication in increasing platelet count in adult ITP patients.