Background and Aim: Association between gastroesophageal reflux (GER) and respiratory diseases has been known for a long time. There are few epidemiological studies on general population in the world, and little is known about a possible association between respiratory symptoms and reflux in Iran . Method: A sample of 5492 adults (more than 20 years old) was randomly selected for the study, from them 4762 subjects agreed to take part (86.7%). The medical students interviewed all of the subjects. Results: The prevalence of monthly reflux symptoms and active asthma were 25.5% and 6.7% respectively. The correlation between reflux and asthma had a confidence interval of (2.60–3.43 ) and an odds ratio of 2.99. The correlation between chronic bronchitis and reflux had a confidence interval of (1.43–2.58) and an odds ratio of 1.92. Conclusion: These findings indicates that epigastric pain in many asthmatic and chronic bronchitis patients may be due to reflux
