BACKGROUND: Side effects of long-term acid suppression have increased the scholars' interest in nonpharmacologic intervention. AIMS: We summarized an umbrella review of the association between environmental factors and gastroesophageal reflux disease (GERD) and assessed their credibility. METHODS: We appraised systematic reviews and meta-analyses. For each meta-analysis, we considered the effect size, 95% confidence interval, the heterogeneity, small-study effects, P-value for excess significance and largest study significant, then we graded the evidence according to Assessment of Multiple Systematic Reviews and the GRADE assessment. RESULTS: 23 publications met the inclusion criteria (13 meta-analyses and 10 systematic reviews), which evaluated 24 environmental factors. Among observational studies, we identified 7 risk factors: overweight/obesity [GERD/erosive esophagitis (EE)/GERD symptom], central adiposity [EE], smoking [GERD], alcohol [GERD/EE/non-erosive reflux disease (NERD)], NSAID [GERD], coffee [EE], Helicobacter pylori eradication [EE], and 1 protective factor: physical activity [GERD], this was based on a suggestive evidence of credibility. Across intervention studies, we identified 1 risk factor-Helicobacter pylori eradication [GERD] and 1 protective factor-breathing exercises [GERD], evidence for both was low grade. CONCLUSIONS: We found varying levels of evidence for different environmental factors of GERD. None of them was proven to be convincing or highly recommended.