Background: Helicobacter pylori (H. pylori) eradication therapy is known to increase the platelet count, but in immune thrombocytopenic purpura (ITP), the effect of H. pylori infection on the response to treatment is not clear. This study aims to determine whether the response to the first–line treatment is affected by the states of H. pylori–positivity and –negativity in ITP patients. Methods: Adult newly diagnosed or chronic ITP patients who had not received eradication therapy for H. pylori infection were included. Characteristics of the patients, presence and severity of bleeding, initial platelet count, administered treatments, and treatment response rates were inspected. Results: Of 119 total patients, 32 (26.9%) were H. pylori–positive, 87 (73.1%) were H. pylori–negative. The most common treatment was standard–dose steroid in both groups (62.5% vs 68.9%, p=0.524). Rates of complete response, partial response, no response were comparable for the two groups (respectively, 75% vs 73.6%, and 18.8% vs 19.5%, and 6.2% vs 6.9%), and there was no significant difference between the groups (p=0.283). Conclusion: It can be stated according to the present study that; in ITP patients in whom treatment is indicated, the response to the first–line treatment without the administration of H. pylori eradication therapy is comparable between H. pylori–positive and H. pylori–negative patients. Keywords: Helicobacter pylori, immune thrombocytopenic purpura, first-line treatment