Background and Objective: Gastroesophageal reflux disease (GERD) after one anastomosis gastric bypass (OAGB) is a controversial topic. Most studies were not able to precisely demonstrate the presence of bile reflux and its consequences after OAGB. However, historical experience with the Billroth II anastomosis suggests that bile reflux after OAGB may be a problem, with the concern that GERD after OAGB might cause the development of Barrett's esophagus and esophageal cancer. This is a narrative review of the literature aiming to bring an overview on the stage of the art of OAGB and to support the reasonable concern about GERD after the procedure and the need for more studies in the field. Methods: A research on PubMed, Medline, and Google Scholar was performed. The key words combined were "Gastroesophageal reflux", "One Anastomosis Gastric Bypass", "Barrett's esophagus", "Gastric cancer", "Esophageal cancer", and "Bile reflux". Articles written in English were eligible, the year of publication and the type of the study was not limited. Key Content and Findings: Despite there is not strong evidence that OAGB can favor GERD it is important to look back on what we have seem with gastrectomy, Billroth II anastomosis, and the consequences of long -term bile reflux. However, OAGB is clearly a different procedure, as well as patients living with obesity do not have necessary the same characteristics than those who were submitted to a gastrectomy. Conclusions: Bile reflux after OAGB is a concern to experienced surgeons. More studies with better methodology and long -term follow up are necessary to bring light to this controversial topic. Until them, surgeons must be very rigorous in the patient's follow-up.