Background and aim Chronic rhinosinusitis (CRS) is an upper respiratory-tract disease, which affects general health of patients. This study aims to detect Helicobacter pylori in paranasal sinus specimens of patients having CRS and to approve if there is a relation between H. pylori and CRS. Patients and methods This study included 60 patients complaining of nasal and gastroesophageal reflux disease (GERD) symptoms. According to computed tomography findings, patients were divided into group A: this included 30 patients, they had chronic sinusitis, or nasal polyp and GERD symptoms, and group B: this included 30 patients, they had inferior-turbinate hypertrophy without sinus affection and with GERD symptoms. All patients were submitted to endoscopic surgery, under general anesthesia, and the samples of diseased sinus mucosa or nasal polyp in group A and the samples of inferior turbinate in group B were sent for histopathological and microbiological examination. Results In group A, rapid urease test (RUT) was positive in 10 (33.3%) patients and negative in 20 (66.6%) patients, while immunohistochemistry (IHC) was positive in five (16.5%) patients and negative in 25 (83.5%) patients. In group B, RUT was positive in five (16.5%) patients and negative in 25 (83.5%) patients, while IHC was positive in 0 (0%) patients and negative in 30 (100%) patients. There was a significant difference between RUT and IHC results in both groups (P=0.032). Conclusion H. pylori infection has possible role in chronic sinusitis. More studies are required to confirm this correlation.