Introduction: Chronic suppurative otitis media (CSOM) is considered one of the most common causes of acquired hearing impairment in developing countries. CSOM is a multifactorial persistent inflammatory disease of the middle ear. A distinct pathophysiologic mechanism linking allergic rhinitis (AR) and CSOM remains to evolve. The purpose of this study was to investigate the association between AR and CSOM in adults.This was a case-control study. Materials and Methods: The subjects were ۶۲ adults (۲۳ male, ۳۹ female) with established CSOM and ۶۱ healthy controls.CSOM was diagnosed when there was a history of chronic (persisting for at least ۳ months) otorrhea, accumulation of mucopurulent exudates in the external auditory canal or middle ear and/or perforated tympanic membrane on otoscopy. All participants were evaluated for the presence of AR by clinical evaluation of allergic symptoms, and underwent a skin-prick test for ۲۳ common regional allergens. Statistical analysis was performed using SPSS version ۱۶. Results: The prevalence of clinical rhinitis (allergic and non-allergic) was significantly higher among the cases compared with controls (۶۲.۵% vs. ۳۷.۵%, P=۰.۰۲). The prevalence of AR (proven by positive skin-prick test) was also significantly higher among affected adults than controls (۲۴.۶% and ۱۳.۸%, respectively). Adjusting for age, a logistic regression model showed that there was a significant difference between the two groups. Patients with AR and non-AR were at ۳.۲۷- (۹۵% CI=۱.۱۵–۹.۲۹; P=۰.۰۳۶) and ۲.۵۷-(۹۵% CI=۱.۰۱–۶.۵۷; P=۰.۰۴۸) fold increased risk of developing CSOM, respectively, compared with healthy individuals. Conclusion: The study showed a higher prevalence of AR in CSOM patients than in controls. It may be valuable to evaluate and control this factor in these patients.