To evaluate a possible relationship between glaucoma and Helicobacter pylori (H. pylori) infection. One hundred thirty seven patients with Primary Open Angle Glaucoma (POAG), eighty-five control subjects and two hundred fifty subjects with gastric symptoms participated in a prospective, nonrandomized, comparative study. The presence of H. pylori infection in glaucoma patients, and glaucoma prevalence in H. pylori infected patients were studied. In the first part of the study, serum immunoglobulin (Ig) G and Ig A levels of H. pylori in 137 patients with POAG and in 85 normal subjects were measured by using enzyme linked immunosorbent assay kit. In the second part of the study, 250 subjects who have gastric complaints and undergone diagnostic upper gastrointestinal endoscopy were enrolled. Of the 250 subjects, 155 subjects were histological H. pylori (+) and 95 subjects were H. pylori (-) and checked for diagnosis of glaucoma or ocular hypertension. Levels of serum Ig G and Ig A antibodies against H. pylori (p < 0.001) and the presence of Ig G and Ig A seropositivity for H. pylori in POAG patients were higher compared to control (p < 0.05, p < 0.001, respectively). In the H. pylori (+) group, glaucoma was found in one and ocular hypertension in two patients. In the H. pylori (-) group, ocular hypertension was found in one patient. There was no statistical difference with respect to the presence of glaucoma between H. pylori infected and noninfected patients. H. pylori infection does not seem to be a causative factor for glaucoma. The seropositivity of H. pylori infection in patients with POAG warrants to be clarified in further studies.