Frequent gastroesophageal reflux (GER) causes chronic inflammation and damages esophageal mucosa, which can lead to Barrett's esophagus. It has also been consistently found to be a strong risk factor for esophageal adenocarcinoma. The prevalence of GER appears to vary; however, population-based Australian studies investigating the symptoms are limited. This study aimed to estimate the population prevalence and identify the determinants of frequent GER symptoms in the Australian population. Self-reported information on the frequency of reflux symptoms were collected from 1,580 adults from a population register. We estimated age- and sex-standardized prevalence of occasional (